Maybe

Briarpack Alpha

Flash (You may cast this spell any time you could cast an instant.)
When Briarpack Alpha enters the battlefield, target creature gets +2/+2 until end of turn.

Merciless Predator

At the beginning of each upkeep, if a player cast two or more spells last turn, transform Merciless Predator.

Reckless Waif

At the beginning of each upkeep, if no spells were cast last turn, transform Reckless Waif.

Reckless Waif // Merciless Predator

Sinuous Predator

Sinuous Predator can't be blocked by more than one creature.

Kessig Prowler

Kessig Prowler // Sinuous Predator

Nightpack Ambusher

Flash
Other Wolves and Werewolves you control get +1/+1.
At the beginning of your end step, if you didn't cast a spell this turn, create a 2/2 green Wolf creature token.

Gatstaf Howler

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Gatstaf Howler.

Gatstaf Shepherd

At the beginning of each upkeep, if no spells were cast last turn, transform Gatstaf Shepherd.

Gatstaf Shepherd // Gatstaf Howler

Increasing Savagery

Put five +1/+1 counters on target creature. If this spell was cast from a graveyard, put ten +1/+1 counters on that creature instead.
Flashback {5}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Curse of Stalked Prey

Enchant player
Whenever a creature deals combat damage to enchanted player, put a +1/+1 counter on that creature.

Don't Have

The Celestus

If it's neither day nor night, it becomes day as The Celestus enters the battlefield.
{T}: Add one mana of any color.
{3}, {T}: If it's night, it becomes day. Otherwise, it becomes night. Activate only as a sorcery.
Whenever day becomes night or night becomes day, you gain 1 life. You may draw a card. If you do, discard a card.

Wolfrider's Saddle

When Wolfrider's Saddle enters the battlefield, create a 2/2 green Wolf creature token, then attach Wolfrider's Saddle to it.
Equipped creature gets +1/+1 and can't be blocked by more than one creature.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Getting

Sharpened Pitchfork

Equipped creature has first strike.
As long as equipped creature is a Human, it gets +1/+1.
Equip {1}

Lord of the Ulvenwald

Other Wolves and Werewolves you control get +1/+1.
Whenever Lord of the Ulvenwald attacks, add {R} or {G}. Until end of turn, you don't lose this mana as steps and phases end.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Kessig Naturalist

Whenever Kessig Naturalist attacks, add {R} or {G}. Until end of turn, you don't lose this mana as steps and phases end.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Kessig Naturalist // Lord of the Ulvenwald

Mountain

Ravager of the Fells

Trample
Whenever this creature transforms into Ravager of the Fells, it deals 2 damage to target opponent or planeswalker and 2 damage to up to one target creature that player or that planeswalker's controller controls.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ravager of the Fells.

Huntmaster of the Fells

Whenever this creature enters the battlefield or transforms into Huntmaster of the Fells, create a 2/2 green Wolf creature token and you gain 2 life.
At the beginning of each upkeep, if no spells were cast last turn, transform Huntmaster of the Fells.

Huntmaster of the Fells // Ravager of the Fells

Immerwolf

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Each other creature you control that's a Wolf or a Werewolf gets +1/+1.
Non-Human Werewolves you control can't transform.

Exuberant Wolfbear

Whenever Exuberant Wolfbear attacks, you may change the base power and toughness of target Human you control to Exuberant Wolfbear's power and toughness until end of turn.

Wildblood Pack

Trample
Attacking creatures you control get +3/+0.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Wildblood Pack.

Instigator Gang

Attacking creatures you control get +1/+0.
At the beginning of each upkeep, if no spells were cast last turn, transform Instigator Gang.

Instigator Gang // Wildblood Pack

Lambholt Butcher

At the beginning of each upkeep, if a player cast two or more spells last turn, transform Lambholt Butcher.

Lambholt Pacifist

Lambholt Pacifist can't attack unless you control a creature with power 4 or greater.
At the beginning of each upkeep, if no spells were cast last turn, transform Lambholt Pacifist.

Lambholt Pacifist // Lambholt Butcher

Werewolf of Ancient Hunger

Vigilance, trample
Werewolf of Ancient Hunger's power and toughness are each equal to the total number of cards in all players' hands.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Werewolf of Ancient Hunger.

Sage of Ancient Lore

Sage of Ancient Lore's power and toughness are each equal to the number of cards in your hand.
When Sage of Ancient Lore enters the battlefield, draw a card.
At the beginning of each upkeep, if no spells were cast last turn, transform Sage of Ancient Lore.

Sage of Ancient Lore // Werewolf of Ancient Hunger

Forest

Snarling Wolf

{1}{G}: Snarling Wolf gets +2/+2 until end of turn. Activate only once each turn.

Moonlight Hunt

Choose target creature you don't control. Each creature you control that's a Wolf or a Werewolf deals damage equal to its power to that creature.

Krallenhorde Killer

{3}{G}: Krallenhorde Killer gets +4/+4 until end of turn. Activate only once each turn.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Krallenhorde Killer.

Wolfbitten Captive

{1}{G}: Wolfbitten Captive gets +2/+2 until end of turn. Activate only once each turn.
At the beginning of each upkeep, if no spells were cast last turn, transform Wolfbitten Captive.

Wolfbitten Captive // Krallenhorde Killer

Howlpack Resurgence

Flash (You may cast this spell any time you could cast an instant.)
Each creature you control that's a Wolf or a Werewolf gets +1/+1 and has trample.

Village Reavers

Wolves and Werewolves you control have haste.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Village Watch

Haste
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Village Watch // Village Reavers

Varis, Silverymoon Ranger

Reach, ward {1}
Whenever you cast a creature or planeswalker spell, venture into the dungeon. This ability triggers only once each turn. (To venture into the dungeon, enter the first room or advance to the next room.)
Whenever you complete a dungeon, create a 2/2 green Wolf creature token.

Arlinn, Embraced by the Moon

+1: Creatures you control get +1/+1 and gain trample until end of turn.
−1: Arlinn, Embraced by the Moon deals 3 damage to any target. Transform Arlinn, Embraced by the Moon.
−6: You get an emblem with "Creatures you control have haste and '{T}: This creature deals damage equal to its power to any target.'"

Arlinn Kord

+1: Until end of turn, up to one target creature gets +2/+2 and gains vigilance and haste.
0: Create a 2/2 green Wolf creature token. Transform Arlinn Kord.

Arlinn Kord // Arlinn, Embraced by the Moon

Fearless Pup

First strike
Boast — {2}{R}: Fearless Pup gets +2/+0 until end of turn. (Activate only if this creature attacked this turn and only once each turn.)

Timber Shredder

Trample
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Timber Shredder.

Hinterland Logger

At the beginning of each upkeep, if no spells were cast last turn, transform Hinterland Logger.

Hinterland Logger // Timber Shredder

Wolfir Silverheart

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Wolfir Silverheart is paired with another creature, each of those creatures gets +4/+4.

Moonmist

Transform all Humans. Prevent all combat damage that would be dealt this turn by creatures other than Werewolves and Wolves. (Only double-faced cards can be transformed.)

Full Moon's Rise

Werewolf creatures you control get +1/+0 and have trample.
Sacrifice Full Moon's Rise: Regenerate all Werewolf creatures you control.

Waxing Moon

Transform up to one target Werewolf you control. Creatures you control gain trample until end of turn.

Ranger Class

(Gain the next level as a sorcery to add its ability.)
When Ranger Class enters the battlefield, create a 2/2 green Wolf creature token.
{1}{G}: Level 2
Whenever you attack, put a +1/+1 counter on target attacking creature.
{3}{G}: Level 3
You may look at the top card of your library any time.
You may cast creature spells from the top of your library.

Ancient Grudge

Destroy target artifact.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Howlpack Alpha

Each other creature you control that's a Werewolf or a Wolf gets +1/+1.
At the beginning of your end step, create a 2/2 green Wolf creature token.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Howlpack Alpha.

Mayor of Avabruck

Other Human creatures you control get +1/+1.
At the beginning of each upkeep, if no spells were cast last turn, transform Mayor of Avabruck.

Mayor of Avabruck // Howlpack Alpha

Triumph of Ferocity

At the beginning of your upkeep, draw a card if you control the creature with the greatest power or tied for the greatest power.

Neck Breaker

Attacking creatures you control get +1/+0 and have trample.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Neck Breaker.

Breakneck Rider

At the beginning of each upkeep, if no spells were cast last turn, transform Breakneck Rider.

Breakneck Rider // Neck Breaker

Tovolar, the Midnight Scourge

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
{X}{R}{G}: Target Wolf or Werewolf you control gets +X/+0 and gains trample until end of turn.
Nightbound

Tovolar, Dire Overlord

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
At the beginning of your upkeep, if you control three or more Wolves and/or Werewolves, it becomes night. Then transform any number of Human Werewolves you control.
Daybound

Tovolar, Dire Overlord // Tovolar, the Midnight Scourge

Young Wolf

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Timber Wolves

Banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Krallenhorde Howler

Creature spells you cast cost {1} less to cast.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Krallenhorde Howler.

Duskwatch Recruiter

{2}{G}: Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of each upkeep, if no spells were cast last turn, transform Duskwatch Recruiter.

Duskwatch Recruiter // Krallenhorde Howler

Ironfang

First strike
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ironfang.

Village Ironsmith

First strike
At the beginning of each upkeep, if no spells were cast last turn, transform Village Ironsmith.

Village Ironsmith // Ironfang

Ulrich, Uncontested Alpha

Whenever this creature transforms into Ulrich, Uncontested Alpha, you may have it fight target non-Werewolf creature you don't control.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ulrich, Uncontested Alpha.

Ulrich of the Krallenhorde

Whenever this creature enters the battlefield or transforms into Ulrich of the Krallenhorde, target creature gets +4/+4 until end of turn.
At the beginning of each upkeep, if no spells were cast last turn, transform Ulrich of the Krallenhorde.

Ulrich of the Krallenhorde // Ulrich, Uncontested Alpha

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Vildin-Pack Alpha

Whenever a Werewolf enters the battlefield under your control, you may transform it.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Vildin-Pack Alpha.

Geier Reach Bandit

Haste
At the beginning of each upkeep, if no spells were cast last turn, transform Geier Reach Bandit.

Geier Reach Bandit // Vildin-Pack Alpha

Terror of Kruin Pass

Double strike
Werewolves you control have menace. (They can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Terror of Kruin Pass.

Kruin Outlaw

First strike
At the beginning of each upkeep, if no spells were cast last turn, transform Kruin Outlaw.

Kruin Outlaw // Terror of Kruin Pass

Game Trail

As Game Trail enters the battlefield, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters the battlefield tapped.
{T}: Add {R} or {G}.

Werewolf Ransacker

Whenever this creature transforms into Werewolf Ransacker, you may destroy target artifact. If that artifact is put into a graveyard this way, Werewolf Ransacker deals 3 damage to that artifact's controller.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Werewolf Ransacker.

Afflicted Deserter

At the beginning of each upkeep, if no spells were cast last turn, transform Afflicted Deserter.

Afflicted Deserter // Werewolf Ransacker

Spirit of the Hunt

Flash
When Spirit of the Hunt enters the battlefield, each other creature you control that's a Wolf or a Werewolf gets +0/+3 until end of turn.

Moonrise Intruder

Menace (This creature can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Moonrise Intruder.

Village Messenger

Haste
At the beginning of each upkeep, if no spells were cast last turn, transform Village Messenger.

Village Messenger // Moonrise Intruder

Ulvenwald Primordials

{G}: Regenerate Ulvenwald Primordials.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ulvenwald Primordials.

Ulvenwald Mystics

At the beginning of each upkeep, if no spells were cast last turn, transform Ulvenwald Mystics.

Ulvenwald Mystics // Ulvenwald Primordials

Arlinn, the Moon's Fury

Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)
+2: Add {R}{G}.
0: Until end of turn, Arlinn, the Moon's Fury becomes a 5/5 Werewolf creature with trample, indestructible, and haste.

Arlinn, the Pack's Hope

Daybound (If a player casts no spells during their own turn, it becomes night next turn.)
+1: Until your next turn, you may cast creature spells as though they had flash, and each creature you control enters the battlefield with an additional +1/+1 counter on it.
−3: Create two 2/2 green Wolf creature tokens.

Arlinn, the Pack's Hope // Arlinn, the Moon's Fury

Werewolf Pack Leader

Pack tactics — Whenever Werewolf Pack Leader attacks, if you attacked with creatures with total power 6 or greater this combat, draw a card.
{3}{G}: Until end of turn, Werewolf Pack Leader has base power and toughness 5/3, gains trample, and isn't a Human.

Deranged Outcast

{1}{G}, Sacrifice a Human: Put two +1/+1 counters on target creature.