Vigilance
Whenever another creature you control enters, Leaf-Leap Guide and that creature perpetually get +1/+1.
, : Return another target creature you control to its owner's hand.

Whenever one or more Mice you control attack, draft a card from Recruit Instructor's spellbook.
Valiant — Whenever Recruit Instructor becomes the target of a spell or ability you control for the first time each turn, create a 1/1 white Mouse creature token.

When Euru, Acorn Scrounger enters, you may forage. When you do, conjure a card named Chitterspitter onto the battlefield.
Whenever one or more Squirrels you control deal combat damage to a player, you may sacrifice a token. If you do, put an acorn counter on each permanent you control named Chitterspitter.

Convoke
At the beginning of your end step, if you control a tapped creature, seek a nonland permanent card with mana value X or less, where X is the number of tapped creatures you control. Put that card onto the battlefield.

When Indris, the Hydrostatic Surge enters, conjure a card named Lightning Bolt into your library. It perpetually gains storm. Then shuffle.
Whenever you cast an instant or sorcery spell, draw a card.