Okay, I'm going to shoot from the hip here, so this might not be as well thought out as some of my other entries in this game.
Clockwise from upper left: Alec Newman, Keith David, Kenneth Johnson, Andy Serkis, John Rhys-Davies, Laura Elena Harring
Alec Newman as
Lion-O - Best known as Paul Atreides, the messianic Muad'dib of TV's
Dune miniseries (and its sequel
Children of Dune) would channel his ability to radiate brooding intensity developed from the burden of great expectations.
Keith David as
Panthro - This ubiquitous character actor brings in his experience playing ferociously noble military types from films like
Platoon and
Armageddon to play the cunning mechanic and hot-tempered warrior.
Kenneth Johnson as
Tigra - On FX's
The Shield, Johnson played Curtis Lemansky --- the relatively level-headed wall between the headstrong individualism of Shane Vendrell and the brutal leadership of Vic Mackey. As Tigra, he brings that experience to play the responsible illusionist and Lion-O's second in command.
Laura Elena Harring as
Cheetara - Laura Harring is probably best remembered for her role as Rita/Camilla in David Lynch's
Mulholland Drive. With her diverse resume, Harring brings aspects of maternal concern, smoldering sexuality and soulful intuition to her role as Cheetara.
John Rhys-Davies as
Jaga - With his commanding vocal presence, Rhys-Davies is essentially the perfect choice to give voice to the spectral mentor... and he could play the part in live-action too.
Andy Serkis as
Mumm-Ra - Before you say "cop-out!" bear in mind that Mumm-Ra is essentially a pathetic decrepit old man who hulks out into a monstrous warrior --- I tried looking at older actors to fit the bill, but most were too campy --- but it's a performance that's within easy reach for Serkis, whose talent in playing Gollum in LOTR, lay primarily in his ability to emphasize the downtrodden patheticness of the character.
David Kaufman as
Snarf - David Kaufman specializes in squeaky vocal performances and is well-liked for his role as Danny Fenton in Nickelodeon's
Danny Phantom. VO nerds might have noticed that he has "played Michael J. Fox" in cartoons like
Stuart Little and
Back to the Future: The Animated Series. In short, his entire resume makes him a great candidate to replace Robert McFadden in this role.