Clifford, Alpha Predator

Riot, Trample
This spell can't be countered.
Whenever you deal 15 or more damage in one
combat step for the first time a turn, untap all attacking creatures you control, and theres an additional combat step this turn.
{r}{r}{g}{g}; creatures you control gain trample,
haste, and +1/+1 until end of turn.