When Nickelodeon's hit "Teenage Mutant Ninja Turtles" animated series returns for its new season, some familiar voices will join the show for a fifth season, causing the titular heroes no end of trouble.

Announced by the network at Comic-Con International in San Diego, David Tennant, Michael Dorn and Peter Stomrare will guest star as The Fugitoid, Lord Dregg and Captain Mozar. And while Tennant's character is traditionally an ally of Leo, Don, Raph and Mike, the latter two will no doubt make their life much more difficult.

The network's official guest star/character description is as follows:

  • David Tennant (Dr. Who) guest stars as The Fugitoid who was once an alien scientist named Dr. Honeycutt, but after his body was destroyed, his brain was saved and placed into the body of a robot.
  • Peter Stormare (Fargo) guest stars as Lord Dregg, an arrogant, insectoid crime lord. When the Turtles incur his wrath, he becomes one of their most dangerous enemies.
  • Michael Dorn (Star Trek) stars as Captain Mozar, the supreme Commander of the Triceraton Fleet. He is a cunning and brutal military commander who answers only to the Triceraton Emperor.
  • Additional guest stars debuting later this year include: Lance Henriksen (Aliens) as Zog, a scout for the alien Triceraton army; Ron Perlman (Sons of Anarchy) as Armaggon, a vicious, bounty-hunter robo-shark with a taste for turtle; and Zelda Williams (The Legend of Korra) as fan-favorite Mona Lisa, a highly skilled Salamandrian warrior.