 The babies discover a tiny lizard in Tommy Pickles ' backyard that they are convinced is the offspring of Reptar , a fictitious green dinosaur and main character of many action movies of which the Rugrats are fond . After learning about the extinction of the dinosaurs , Tommy decides to return the lizard to Reptar just as his family has purchased tickets for a musical ice show based on the character . After Tommy 's parents and grandfather have fallen asleep , the babies sneak into the ice rink and present the lizard to Leo , the actor portraying Reptar , who coincidentally happens to possess a phobia of lizards . Stu Pickles , Tommy 's father , sees the rugrats and must retrieve them from the ice rink . 
