Peter Puppy is small, fluffy and pleasant to be around generally. However Peter has one small problem. Whenever he gets hurt, angry, scared or stressed, Peter can't control Himself - and to every ones horror, mutates into quite the opposite - A huge fang-toothed drooling monster, which will maul anyone or anything around him until the danger or threat has passed.
Peter was found by Jim when he crash landed on Peter's home planet through an inter-dimensional black hole. With his rocket damaged, Jim needed some help to get out of the predicament. Peter being small and seemingly defenceless told Jim that if he helped him travel back to his home, he would try to help. Even it did mean Jim got very badly mauled several times on the way.
Eventually Peter helped Jim escape his home world, by finding a powerful turbo engine and a dimension shifter unit - that just happened to be in the space debris around his small make-shift hut. Realising that he had a chance at last to escape his turbulent home world, Peter joined Jim on his travels.
It must be said that peter is not incredibly brave...it doesn't take a lot to get him stressed out, at which time it's time to run. But nevertheless Peter is quite independent - his family of six hundred tiny puppies is homage to that - and is always there to help out, if the need arises.