Savannah

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Giant Growth

Target creature gets +3/+3 until end of turn.

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Taiga

King of the Pride

Savannah Lions

Mountain

Isamaru, Hound of Konda

Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.
Whenever you cast a Cat spell, create a 1/1 white Dog creature token.
{R}{G}{W}, {T}: Rin and Seri deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Plains

Generous Stray

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Harmonize

Revitalize

Chandra's Magmutt

{T}: This creature deals 1 damage to target player or planeswalker.