Evolution Facility

At the beginning of combat on your turn, put a
+1/+1 counter on target creature you control.
You may sacrifice it. If you do, search your
library for a creature card with mana value X or
less and put it onto the battlefield, then shuffle,
where X is the number of counters on that
creature.
{1}{g/u}{g/u}: Put a +1/+1 counter on target creature.