Thromok the Insatiable

Devour X, where X is the number of creatures devoured this way (As this creature enters, you may sacrifice any number of creatures. It enters with X +1/+1 counters on it for each of those creatures.)

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap this creature for mana, it deals 1 damage to each opponent.

Radha, Heir to Keld

Whenever Radha attacks, you may add {R}{R}.
{T}: Add {G}.

Llanowar Elves

Elvish Mystic

Artifact Mutation

Destroy target artifact. It can't be regenerated. Create X 1/1 green Saproling creature tokens, where X is that artifact's mana value.

Ruby, Daring Tracker

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Ruby attacks while you control a creature with power 4 or greater, Ruby gets +2/+2 until end of turn.
{T}: Add {R} or {G}.