Pets make your MC look like a nice character. Everyone knows that animal lovers are always good people. Your MC should have a pack of dogs, several cats (stray or otherwise), a few tanks of fish or hermit crabs, a parrot, an iguana, an orphaned squirrel or two, a flock of geese, some turtles, gold finches, a pair of horses, a chicken, three mice, a girbil, two hamsters, a hawk, a dolphin, a fox, a tigeress, a jaguar, and a dragon, for good measure.
Certain animals reek of evilness and should never be owned by anyone but the bad guy. Tarantulas, Snakes, giant three headed dogs, and fat white lap-cats = EVIL.