Harvest Mage

{G}, {T}, Discard a card: Until end of turn, if you tap a land for mana, it produces one mana of a color of your choice instead of any other type and amount.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters the battlefield, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.