Real Name: Cassius
Occupation: Criminal
Marital Status: Single
Base of Operations: Gotham City
Height: N/A
Weight: N/A
Eyes: N/A
Hair: N/A
First Appearance: Batman: Shadow of the Bat #27 (May 1994)
Created By: N/A

After the Mud Pack, Payne and Fuller fell in love and eventually became withdrawn and had a child together named Cassius "Clay" Payne, who became the fifth Clayface. The boy is separated from his parents and held in a government laboratory. The full extent of his powers are unknown. The name "Cassius" is a pun on "Cassius Clay", the birthname of legendary boxer Muhammad Ali.

Currently, the bio status of Cassius shows that if a piece of him is separated from his body, it can grow a mind of its own, but it mostly thinks in a retarded form of what Cassius wants. If bonded with another human (i.e. Claything), the piece can give that human clayface-like abilities, such as become like clay, being able to withstand bullets and other harm, and could also manifest Payne's ability to melt objects, but all this person would have to do is just think it. It is unknown if a person can gain different abilities when bonded with a piece of Cassius.

Recently, Cassius has now taken on the clay-like appearance of his mother and father, but he looks more like Basil Karlo than either of his parents. He can only stay in Clayface mode while awake, similar to the Teen Titans villain Plasmus in the animated show.