Carl

"This reminds me of my Icelandic boyhood."

- Carl's unlock message

Carl Carlson is a character in the Plant Workers collection who comes with the Springfield Buddhist Temple. He is Lenny's best friend; and Lenny is also unlocked with the Springfield Buddhist Temple.

Simpsons Wiki Description
Carlton "Carl" Carlson MPhys or "the black one" (as referred to by Homer Simpson as a simpler way of remembering who he is) is a safety operations supervisor from the sector 7G of the Springfield Nuclear Power Plant, where he works alongside his childhoood friends Lenny and Homer. Carl is a self-restrained organized (although not maniac about it, like Frank Grimes) employee and likes to call himself "an urban Lenny". It was in fact hinted to in the series that him and Lenny could actually be more than just friends. Carl also attended Springfield A&M University. Mr Burns once implied that he was a war hero.
 * Read the full article here at Simpsons Wiki.

Trivia

 * There is an in-game decoration that represents Carl - Mount Carlmore in which his face has been carved into a 12x12 piece of rock.