Bostonian that frequent's Sam Malone's bar Cheers.
Though written by Fabian Nicieza and drawn by Greg Capullo, Cliff was a character on the popular show "Cheers" (played by John Ratzenberger) before appearing in the pages of X-Force.
Cat-calls Tina Valentino and her "twin," the mutant Copycat, as they walk into the bar. Sadly, Cliff and the bar patrons are some of the last people to see Tina before she dies when Sluggo attacks her and Copycat shortly after they leave the bar.
Also makes a guest appearance in a Simpson's comic.