Like most dogs, Spike is a friendly, loyal mutt whose main interest is food and his wife Fifi. Stu and Didi consider him a dumb, but pleasant member of the family. Yet Spike is often most aware of what the Rugrats are up to than they are. He and Tommy share interpid interest in, and curiosity about, the world around them. When he's not rescuing Tommy from impending doom. Spike often takes the babies on magnifigant adventures through the neighborhood adventures which Stu and Didi are never aware of.