Corgi is a "regular" worker in the World Government, being something of a Commander amongst the Government Soldiers, as he is seen speaking to the CP9 agents of the security of the Sea Train.
He claims to be able to sniff out pirates (this may be a reference to the type of dog named Corgi, Pembroke Welsh Corgi and Cardigan Welsh Corgi [[1]] ). Although he sometimes wonders if his gift is right or not, he has supposedly never missed a pirate.
He constantly tried to get Iceburg to hand over the blueprint of the Pluton. However, he is denied and is seen leaving in a huff. He later appears accompanying the CP9 and watches Robin aboard the Puffing Tom. He was later knocked out by Sogeking during the rescue attempt.
First Appearance: Chapter 328

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