Mister Bloom

Reach, Trample, Lifelink

{x}{b/g}: put a +1/+1 counter on up to X creatures. They became Plants in addition to their other types.

When Mister Bloom attacks, each player sacrifices one or more Plant creatures they control. Bloom gains a number
of +1/+1 counters equal to the number of creature sacrificed this way and you gain that much life.

"...and we grow very, very fast!"