As we meet Mr. Frisby, we find him regaling his friends with tales of his exploits in the war while they hang out in his store. Naturally, they treat his tales with no small amount of skepticism, for he is a master of the tall tale. The tallest of them all, it seems, for even the aliens who have come to the earth to collect a specimen have become interested in him for his accomplishments.
They invite Mr. Frisby to their craft, where he crumbles, but having no understanding of the lie (Galaxy Quest, anyone?), they just don’t get what he is saying. They don’t get it at all.
Lucky for Frisby, he is actually a harmonica player, and even better, he brought it with him. But perhaps best of all, the aliens are not at all fond of the music produced by the mouth organ, so when he pulls it out to play, he can get away from them and back to his store - where his friends are waiting to hear his latest tall tale.
While this is a bit of a slow-mover, it’s not bad. It’s also notable for the appearance of Howard McNear (Floyd the Barber from The Andy Griffith Show).