Bacura

Bacura (バキュラ, Bakyura) is an enormous black panther owned by the Kuja Pirates under Boa Hancock. He is said to be the executioner of the Kuja tribe, and has been serving for them for generations. All of his victims were devoured to the point where even the bones were gone. He was sent to kill Luffy in the battle arena in Amazon Lily Island, and was defeated with a single punch from the Straw Hat Captain.

Source: http://onepiece.wikia.com/wiki/Bacura