Tombstone vs. Clayface

Yes prep time.

I don't think either of these guys is big on prep time.

Besides, there isn't much that Tombstone (who is
a cool character by the way) can do to Clayface.

Clayface wins by knock-out. I dont' think Tombstone
can be killed, though I may be wrong.

Tombstone can't beat killed except maybe by someone as powerful as superman or 2-3 nukes direct hit.
But he doesn't possess weapons that will do any real damage to clayface.
Draw.(at least til tombstone get a better arsenal.)

Yeah they will probably both get bored fighting each other and team up to cause some mayhem.

this is a close fight but they both are boring

Tombstone may be tough to kill, but he can
be knocked around, as Spider-Man has done.