[TOMT] Computer game from the 90s

I don't remember much about this game, but I used to play it all the time. You could choose from different animals, we were always a white and black dog (maybe a robot). You could play a multiplayer mode where you fought someone else on the computer, or a story mode where you traveled through the sewer and the boss had little green toad-like minions. Anyone help?

**Also, if it helps, it was included with a Gateway computer. Like, we got it when we got our computer.