Nassor is highly intelligent, serious, intense 14-year old boy. He takes a darker, more doomsday view on life than the other kids in New Holland. Nassor is instantly skeptical of the rumors surrounding Victor’s experiments with electricity, but once convinced, is zealous in his attempts to obtain Victor’s secrets.
Nassor is one of Victor's classmates. When learning that Victor managed to bring Sparky back to life through the use of lightning, he, Toshiaki, Edgar, Weird Girl and Bob end up copying his research to try and win the upcoming science fair with their own revived animals. He goes to the pet cemetery and the elaborate Egyptian-style mausoleum for his deceased hamster "Colossus" and revives him in the form of a mummy. However, he vastly overestimates the power of his monster pet and Colossus is crushed very easily by the turtle kaiju Shelley when the New Holland Dutch Festival became consumed by chaos of the monster pets. The turtle's roar caused him to trip backwards, wrapping himself in toilet paper and being sealed in an oversized nesting doll, mummy style.
Nassor's voice and appearance are heavily modeled after acclaimed horror icon Boris Karloff.
In the film, Nassor resurrects his deceased pet hamster, Colossus, as a mummy. This, and Nassor's apparent Egyptian heritage, are likely a reference to the 1932 film The Mummy, which featured Boris Karloff as the titular character. Also, toward the climax of the film, he is wrapped up and sealed in a mummy's tomb.