I never noticed it until today, but CP9 was basically the Government version of the Beast/Animal Kingdom pirates. What I mean by this is that every CP9 agent we've seen was based on animals or had animal like Devil Fruits which is why Zoro thought Enies Lobby was some sort of Zoo. I'ma copy and paste it down below.

Every agent also has an animal theme, much like the Seven Warlords of the Sea and the Worst Generation:

Spandam: Panda

Funkfreed: Elephant

Rob Lucci: Leopard

Hattori: Pigeon

Kaku: Giraffe

Kalifa: Sheep

Blueno: Bull

Jabra: Wolf

Kumadori: Lion

Fukurou: Owl

Nero: Weasel

Who's-Who: Despite not being part of the group involved in the Water 7 incident, Who's-Who also sports an animal theme: Smilodon.