Hot tempered and volitile, Ralph prefers action and violence over much else when solving problems. Not that he's unintelligent, he'd just rather bust heads than reason with them. With a basic distrust of just about anyone, he only became friends with Jimmy because he was so honest and nice, and it was Jimmy who talked him into hanging out with Fred.
Despite his tall, menacing stature and generally acting like a jerk, Ralph is really a good guy, and would do anything to help his friends (though, he'd gripe and scowl all the way).
Ralph's the side effect of a corrupt government agency's experiment to create the "perfect" soldier, using bovine DNA. The project was shut down, and the experiments escaped. Later, Ralph would try to take over the world.