A Boy and His Dog (1936)

An obnoxious little toddler boy scares and hits a whimpering puppy in his charge until his mother comes in and puts him to bed and scolds him for his cruelty. Asleep, the boy dreams that the puppy has grown to dinosaur size, bursting through walls, chasing down the brat until retribution looks nigh.

Unfortunately the movie A Boy and His Dog is not yet available on HBO Max.