Thark was a Man-Opossum that appeared in the episode Summer Semester. He wanted to have a battle of the bands to decide what race would rule the world (Man-Snake or Man-Opossum). He played the guitar in Poque's band. His rival, Jessse, played in Marcus' and Horatio's band. Derek theorized that since the master copy of the Summer Semester album allowed both races to form, neither could rule the world if it were destroyed. After the battle was over and they were trying to decide who won, Horatio intentionally broke the master copy CD, destroying both Jessse and Thark. Thus, in ending the plot line of the episode, which began with the formation of the Mega64 band by Horatio and Marcus, Summer Semester has reached its conclusion.
He was portrayed by Luke Chatfield.