WANTED! The GCPD seeks the removal of the rampaging Clayface. Considered a serious threat: do not approach alone.
Look for an "Odd-Looking Joker Goon", he is located in the North-West corner of the effected area (the 2nd 4-way intersection west of Poison Ivy's Greenhouse). He walks from West to East on the North-West corner of that section. Once approached, he would turn into Clayface.
The battle against Clayface is quite similar to Solomon Grundy. Both mainly use melee, leap large distances, do powerful stomps, and have hard Knock Backs. They also hit in the similar range, up to the high 400s.