"A Pet That Can Do Everything" joke

A man enters a pet shop and tells the owner he'd like to buy a pet that can do everything. The owner suggests a dog.
"A dog?" the man replies.
"How about a cat?" the owner says.
"No way! A cat certainly can't do everything. I want a pet that can do everything!" the man replies.
The owner thinks for a moment, then says, "I've got it! A centipede!"
"A centipede?" the man says. "I can't imagine a centipede being able to do everything, but yeah... I'll try a centipede." He pays for the centipede and takes it home.
When they arrive home, he looks at the centipede and says, "Clean the kitchen."
Thirty minutes later, he walks into the kitchen and to his astonishment... it's immaculate! All the dishes and silverware have been washed, dried, and put away; the counter-tops cleaned; the appliances sparkling; the floor waxed.
He then says to the centipede, "Go clean the living room."
Twenty minutes later, he enters the living room. The carpet has been vacuumed; the furniture cleaned and dusted; the sofa pillows plumped; and the plants watered.
The man thinks to himself, "This is the most amazing thing I've ever seen. This really is a pet that can do everything!"
Next, he says to the centipede, "Run down to the corner and get me a newspaper."
The centipede walks out the door. 10 minutes later... no centipede. 20 minutes later... no centipede. 30 minutes later... no centipede. Now the man is beginning to wonder what's going on. The centipede should have been back in a couple of minutes. 45 minutes later... still no centipede!
He can't imagine what could have happened. Did the centipede run away? Did it get run over by a car? Where is that centipede? He goes to the front door, opens it... and there's the centipede sitting right outside.
"What's going on?" he says. "I sent you down to the corner store 45 minutes ago to get me a newspaper.
The centipede says, "I'm goin'! I'm goin'! I'm just puttin' on my shoes!"