A cat is driven crazy by a bizarre cuckoo bird from the clock. Try and try again, the bird gets the best of the cat--who only wants to eat him and have some peace and quiet. The plot, despite the description on IMDb, is MUCH simpler...and a bit different. I would have actually liked it a lot more had it been more like the weird description.
Tex Avery's cartoons for MGM are absolute gems--and are among the best shorts ever made. The problem is that he didn't make more!! They had a level of zany surrealism that put them in a class by themselves. However, I must also admit that although "The Cuckoo Clock" is quite good, it's amazingly tame compared to many of Avery's other cartoons with the studio. Good...not great.