Panda, The Purifier

Defender.
At the begining of each unkeep random creature becomes a wall in addition to its
other types.
{g/u}: put defender counter on target wall.
{g/u}{g/u}: put -1/-1 counter on target wall.
{g/u}{g/u}{g/u},{t}: target wall gets +7/+0 and
trample until end of turn.