Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Predatory Sliver

Prey's Vengeance

Target creature gets +2/+2 until end of turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Runeclaw Bear

Sanctum Weaver

{T}: Add X mana of any one color, where X is the number of enchantments you control.

Savage Swipe

Target creature you control gets +2/+2 until end of turn if its power is 2. Then it fights target creature you don't control. (Each deals damage equal to its power to the other.)

Scale Up

Until end of turn, target creature you control becomes a green Wurm with base power and toughness 6/4.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Squirrel

Scurry Oak

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on this creature, you may create a 1/1 green Squirrel creature token.

Servant of the Scale

This creature enters with a +1/+1 counter on it.
When this creature dies, put X +1/+1 counters on target creature you control, where X is the number of +1/+1 counters on this creature.

Smell Fear

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Target creature you control fights up to one target creature you don't control.

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Squirrel Mob

This creature gets +1/+1 for each other Squirrel on the battlefield.

Squirrel Sanctuary

When this enchantment enters, create a 1/1 green Squirrel creature token.
Whenever a nontoken creature you control dies, you may pay {1}. If you do, return this enchantment to its owner's hand.

Squirrel Sovereign

Squirrel Wrangler

{1}{G}, Sacrifice a land: Create two 1/1 green Squirrel creature tokens.
{1}{G}, Sacrifice a land: Squirrel creatures get +1/+1 until end of turn.

Jumpstart: Historic Horizons