The Talking Ant
He makes friends with the ant, makes up a small bed for it in a matchbox he lines with cotton wool.
Over the years, he teaches it some tricks, and the two of them are close friends.
SHortly before the ten years are up, he finally succeeds in getting the ant to speak. Admittedly, not a great vocabulary and a thick accent, but the ant can talk.
This will be a money spinner, performing with the Talking Ant, and he organises an agent for a world tour.
The day he gets out, on the eve of starting his tour, he goes to a pub to celebrate. Standing at the bar, he gets the ant out of its matchbox, and says to the bartender "Hey, do you see this ant?" The bartender says "Shit, how did that get here?" and squashes it.