Question for Tom and Jerry fans?

Hi. I'm looking for an old Tom and Jerry episode (not the recent "Tom and Jerry Tales" series, but the classic Tom and Jerry franchise from the forties, fifties, and sixties). The only distinctive thing about it which I remember is the following: Tom and Jerry are both being chased (perhaps by Spike the dog, though I honestly don't remember), and both try to hide in a display of toy mice. Jerry of course blends in; Tom, not so much. Anyway, when whoever's chasing them - again, I'm guessing it's Spike - sees this, he pulls the tails of the mice, which prompts them to say "Mama!" Jerry manages to stay out of trouble by simply mimicking the toy mice. Tom, on the other hand, says "Poppa!", and his voice is noticeably deeper than Jerry's. This of course blows their cover, at which point the wacky hijinks resume.

If anybody can provide the name of the episode and, if possible, a link, I'd be grateful. I've tried to find it but to no avail. Ten points to first correct answer.

Thanks in advance!