Catbert is the Director of Human Resources which is shortened in the headers as the "Evil H.R. Director" in the comic strip Dilbert by Scott Adams. To be honest, HR says enough, evil is assumed.
He began as a fat round little cat in a bit-part in 1994, jumping onto Ratbert's head one day. Ratbert walks home with him on his head and the cat pounces on Dilbert's keyboard, hitting Ctrl+Alt+Del in a strangely amusing way (it's the face). Dogbert throws the cat out, despite that cat stating "My mere existence will widen your demographic appeal and make you immortal." In the book Seven Years of Highly Defective People, Adams says: "I worried that adding a cat was not very original. But then I realised nothing else in the strip was original, so I got over it."
It was after this series of strips that Adams received hundreds of emails asking for more Catbert. "The funny thing was," Adams says, "I had not named the character, yet everyone referred to him as Catbert. It seems to me that when hundreds of readers spontaneously name a character for you, it's a good idea to keep him." So in 1995, Catbert returned (now sporting glasses, like Dilbert and Dogbert) to Dilbert's Company With No Name as the Human Resources director. His first job was to taunt the employees with the new organisation chart by waving it in front of their faces and pulling it away before they could see saying "It's fun to play with them before downsizing them."
Catbert's disdain for people is very much the same as Dogbert's, but with a slight difference. Whilst Dogbert wants everyone to serve him as their Supreme Ruler, Catbert takes delight in human suffering. To this end, Catbert is used to satirise all the insane company policies that find their way to Scott Adams' inbox from readers. Dress code seems to be a recurring theme, for example: "My diabolical new dress code will make them question their own sanity" and making all employees wear brooms on their backs to sweep the floor whilst walking around. He also takes pleasure in downsizing and ridiculing those who seek his help: "We re-engineered the counselling process. Now we put you in a big hole and cover you with sand." Catbert is the character who the employees seek if they have a pay dispute or any contractual trouble: "Don't complain to me. You signed the form giving us permission to alter your DNA."
Although it's very easy to distance yourself from the "evil" Catbert character, he is actually a lot like you or I, as a telling strip in 1998 illustrates:
Catbert is sat typing at his computer: "New policy: employees are not allowed to eat at their desks."
Catbert thinks: "Because why? I need a semi-plausible reason."
Catbert types again: "Because I hate you."