Dib is a young, eccentric boy who possesses a fascination with unexplained paranormal phenomenae, such as ghost hunting, Ufology, and cryptozoology, as well as with the supernatural and occult. He intercepted the words spoken at The Great Assigning on planet Conventia in the first episode with his laptop. Six months later, he notices a strange, green "foreign exchange student" enter his classroom. Dib tries his best to convince the world that it is in danger, but nobody believes him due to previous false claims of supernatural beings. Therefore, he must go against all odds to protect his oblivious home from Zim's schemes. Dib can be categorized as the "foil character" of Invader Zim. He contrasts Zim, sharpening their respective characteristics.
Dib is the only child attending Skool who realizes Zim is an alien, and becomes obsessed with sharing it with everyone. Fortunately for Zim, Dib is unpopular at Skool, and none of the other children will even listen to what he says, let alone believe what he is saying. Dib quickly becomes Zim's greatest enemy, and will stop at nothing to deter him from conquering the Earth. Dib has appeared in more episodes than Zim, the main protagonist of the series, though it is obvious Dib is not the main character, even though he either appears or is mentioned in every episode of Invader Zim.