Zelnoc is one of many wizards. However, his spells frequently mess up.
When he is saved by Wiglaf in The New Kid at School, Zelnoc grants Wiglaf's wish, which is for Daisy to talk. Even though the spell allows Daisy to talk, she speaks fluent Pig Latin.
Zelnoc makes a return in Revenge of the Dragon Lady. He is summoned by Wiglaf so he can cast a courage spell to no avail. He soon calls fellow wizard Zizmor to see if he can cast the spell, summoning the whole convention instead. He then disappears with the other wizards.