Togepps are very, very evil. They attempted to destroy all life on Meatworld, starting with the Togepi. Almost every Togepp hates everything, everyone, and anything. Female Togepp will also act quite like Togepi but then kill you.
The Togepp, were fortunately quite weak and the Togepi took them out before they became a large threat. The Taco species also wanted to kill them, but not many Taco knew about them.
The Togepps are currently extinct, though The Core has them ready for any reason.