The premise isn't terribly original, boy, his talking pet, and their wild misadventures, but for people who enjoy surreal cartoons like Cow and Chicken, Ren and Stimpy, Chowder, and the Marvelous Misadventures of Flapjack(the creator of which, Thurop Van Orman, is a producer on the show) it's a welcome addition. The show doesn't quite reach the same greatness of those shows, and scales back some of the absurdity, but manages to still be fairly entertaining.
The cast is fairly decent here, particular note being comedian Chris Hardwick, who plays the snake Craig, and the occasional visit from Arrested Development's Tony Hale as the strange neighbor Mister Noodman, who both breathe a lot of life into otherwise stale archetypes.
The episodes can be, at times, a little overly juvenile and simple, like witnessing a butt transplant, or when a blueberry farmer acts like a gibberish spewing idiot, but shines really well with the absurdist moments and some pretty great jokes.
Though it tries not to be as extreme as the shows that preceded it, like Flapjack and Ren and Stimpy, Sanjay and Craig does suffer from the gross close-ups that these cartoons tend to rely heavily on. It's a bit stale, and at times is just annoying, but doesn't diminish an otherwise fantastic cartoon show.
It's not perfect, it's not even terribly original, but there is some great talent on the show that deserves attention, as well as perhaps the unique situation of having an American cartoon show where the main character is a mixed-race Indian child.