Robert Knepper - who, as the villainous T-Bag on Prison Break, made us shudder by uttering a single sentence - has joined the cast of Heroes.

The scary actor has signed on as the main nemesis for season four of the show. Look for him to appear in at least six episodes.

Knepper will portray Samuel, a charismatic and evil character that possesses a wickedly twisted sense of humor. As any fan of Prison Break can vouch for, the role sounds perfect for this rising star.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.