Mom, an alligator's in my room!

[camillachick]

I recall a cartoon skit in which a boy tries to go to sleep for the night but his dog keeps imitating an alligator and frightening him. Every time the lights go out the alligator comes back! His mom tells him it is his imagination. Eventually he figures it out.
I am looking for descriptions, synopses, transcripts of the sketch to fill in what I can't remember. In particular, what IS the dog singing?

 

[Drtooth]

Off the top of my head, the kid is nervous at the beginning to go to bed, the mother walks in, shuts off the light, and Sparky the dog's shadow turns into an alligator. it starts singing "Imagine me an Alligator (Alligator)" The boy screams, the mother enters the room and says, "I don't see any alligator." The light goes off again, the dog starts singing again, tha pattern repeats for a second time, and the mother explains that it's in his imagine ation. Light shut off, dog sings again "...and you can vie for me to Much yah! I'm afraid a' getting thinner, won't you please become my dinner?" The boy looks and finds his dog and says, "Sparky! It was you all the time."

The mother, from the other room shouts, "What's all that singing in there?"

The boy replies, "oh, nothing mom! It's just your imagination."