Lyle, Lyle, Crocodile by Bernard Waber (1965) Houghton Mifflin

The second book about Lyle the Crocodile.  It completes the storyline in the movie of the same name.  Only here, Mr. Grump lives a couple of doors done from the Prims (not in the same building).  Mr. Grump really does find a way to get Lyle sent to the zoo.  But the resolution is different, yet still satisfying.