Two Patricks appear after the first one rips his SpongeBob costume off. They reappear at the end of the episode, laughing together.
They are created by Patrick when he removes his hand. The clone then chops up the Barg'N-Mart store as the two Patricks laugh.
They were both being created by Plankton's cloning machine, but they got kicked out including Patrick. And at the end of the episode when Karen comes back she saw all the Patrick clones tidying up the Chum Bucket.