The Crunch Bird

There are many variations on this joke, including an old cartoon from the 1960s or 70s. This is just the version I remember off the top of my head:
A woman walks into a pet store looking for a new pet. After a few minutes of browsing around, she's not impressed by what she finds. She's about to walk out, until she looks behind the sales counter and spots the most unusual bird she's ever seen. She asks the salesman what it is.
"Oh, that's a crunch bird!" he says.
"Crunch bird? Never heard of it. What does it do?" she asks.
"Just watch!" he says as he opens the cage. "Crunch bird, chair!" He points to a wooden chair in the corner of the store. The bird flies out of the cage and heads straight for it. Within a matter of seconds, it's reduced to a pile of sawdust.
The woman is impressed, but asks for another demonstration.
"Crunch bird, desk!" the salesman says, pointing at a nearby desk. Once again, the bird aims straight for it, and turns it to dust in a matter of seconds.
"I'll take him!" the woman says.
He tells her it's not for sale, but she begs and tells him money is no object. Finally put in a corner, he accepts her offer, and she takes the bird home.
Her husband arrives home from work a while later and immediately spots the cage.
"What the hell kinda bird is that?" he asks.
"It's a crunch bird!" she says. He's not impressed.
"Oh yeah? Crunch bird, my ass!"