Dogbert is Dilbert's dog. He is a sadistic megalomaniac, dreaming to conquer the world and enslave all humanity. He has accomplished this several times. However, he often quickly relinquishes his post due to boredom, someone foiling his chance, his conviction that people do not deserve to have him as leader due to the ongoing peace that results, or his desire to go nap on a soft pillow. He has made numerous ventures into business as a venture capitalist, consultant, and even Path-E-Tech's C.E.O., duping the pointy-haired boss into paying him huge amounts of money for little or no work, even as he playfully sabotages the company. Dogbert is an adept con artist, extorting from and tricking gullible customers.
Despite his apparent contempt for Dilbert and humans in general, he sometimes steps in to save Dilbert from certain doom showing Dogbert's affection for Dilbert. For example, Dogbert has saved Dilbert from Mr. Tidy, the robber-disguised-as-a-cleaning-man; prevented Dilbert from being executed by Catbert; and rescued Dilbert from the trolls in accounting several times.
Despite his claims to the contrary, Dogbert sometimes shows that he's fond of Dilbert. For example, in one strip, Dilbert commented to Dogbert that his phone was his best friend; Dogbert immediately blew up the phone out of jealousy.