Ralph is a stereotype of security guards (as well as the goon stereotype made famous in earlier Warner Bros. animated shorts), being big, fat and dimwitted. He is badly shaven and seems to be poverty stricken. In Animaniacs, he lives in a trailer park with his wife and son.
Ralph is very incompetent at his job, ending most of his sentences with the word "Umm....DUH". He eats donuts, sucks lollipops, or sleeps instead of catching Yakko, Wakko, and Dot. Ralph has a very childlike state of mind and is very gullible to Yakko, Wakko, or Dot's tricks which is the reason why he can't trap the trio in the water tower.
Ralph has also made other appearances in Tiny Toon Adventures, where he is a security guard that Plucky Duck has problems getting past. In this case he is shown to have more competence than in Animaniacs.