Season of Growth

Whenever a creature you control enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Whenever you cast a spell that targets a creature you control, draw a card.

Rush of Vitality

Target creature gets +1/+0 and gains lifelink and indestructible until end of turn. (Damage dealt by that creature also causes its controller to gain that much life, and it can't be destroyed by damage or effects that say "destroy.")

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Embiggen

Until end of turn, target non-Brushwagg creature gets +1/+1 for each supertype, card type, and subtype it has.

Island

Give In to Violence

Target creature gets +2/+2 and gains lifelink until end of turn.

Swamp

Alchemist's Gift

Target creature gets +1/+1 and gains your choice of deathtouch or lifelink until end of turn. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it. Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Forest

Grotesque Mutation

Target creature gets +3/+1 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Cazur, Ruthless Stalker

Partner with Ukkima, Stalking Shadow (When this creature enters, target player may put Ukkima into their hand from their library, then shuffle.)
Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.

Return to Action

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Essence Infusion

Put two +1/+1 counters on target creature. It gains lifelink until end of turn.

Giant Growth

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

Blessing of Belzenlok

Target creature gets +2/+1 until end of turn. If it's legendary, it also gains lifelink until end of turn.

Ukkima, Stalking Shadow

Partner with Cazur, Ruthless Stalker (When this creature enters, target player may put Cazur into their hand from their library, then shuffle.)
Ukkima, Stalking Shadow can't be blocked.
When Ukkima leaves the battlefield, it deals X damage to target player and you gain X life, where X is its power.

Cruel Feeding

Strive — This spell costs {2}{B} more to cast for each target beyond the first.
Any number of target creatures each get +1/+0 and gain lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)