Gerald (Five Children and It)

From Muppet Wiki

Gerald is a Tyrannosaurus rex in Five Children and It. Gerald is the result of Horace's wish for his dinosaur egg to hatch. The enormous T-rex towers over the child, slobbering all over him (as It notes, Gerald is only two). The dinosaur intends to consume the boy, until Jane's violin music soothes it. The music also irritates It, who causes the prehistoric beast to vanish prematurely.