That was one of a number of ways Filmation was able to get their episodes completed on time despite budget constraints.  Another was to take something already animated for one episode and color it differently for another episode.  I.E., He-Man fights a Red Dragon in one episode, and then later fights a Blue Dragon in a later episode.

I bet it is, never cared to check the name, but it's the new one... I guess from Nickelodeon.

I just see he liking it very much... well he wasn't born in the 80's and is under 4y so he likes it.

Alright so this is conveniently something I wanted to let out for a long time somewhere.

Even without the comic as a source of anything (which shows Skeletor body Mumm-ra, then throw him a bone to body the ASOE, then let him float in his head like Firestorm)

Skeletor still absolutely manhandles Mumm-ra. Mumm-ra has accomplished more evil but is so easily and thoroughly beaten every time. For all the vastness of both his power and advantages he's a pushover. Skeletor almost wins in spite of his disadvantages. He-Man and the MASTERS of the Universe have such a military scientific and raw power advantage over Skeletor, its almost criminal. Snarf.... SNARF sandbagged Mumm-ra over such a plain open flaw. Most with intellect would never try it because most would not be dumb enough to think Mumm-ra is dumb enough to allow it to happen. Mumm-ra also got bodied by a random bounty hunter in his own backyard with relative ease. Mumm-ra gets bodied relatively easily in general. He's a joke of a villain with a lot of power and a lot of flaws.

Skeletor fights He Man and a squad so powerful, they literally call themselves the masters of the universe with no real equal until She-Ra shows up (but that's neither here nor there).
Mumm-ra, on the other hand, fights the vestiges of a extinct race. The vestiges are a literal man-child, Lion-O, a child aged into a man's body, and 5-9 servants (If you really wanna count the Ghost Jaga and Snarf, which you should because again, Snarf sandbagged Mumm-ra. I'll never let that go). And yes I say servants because they basically have to listen to Lion-O, who, being a literal man-child, for the longest time made too many near fatal mistakes). They don't have anywhere near the resources, tech, or raw power He-Man and his crew has at their disposal.
Skeletor, is significantly smarter and a better person to wield any sort of power over Mumm-ra. Almost all Skeletor's minions are trash but he has no choice in the matter. Mumm-ra has a huge disposal at with him and still loses every damn time. Sometimes his henchmen outperform him. Unreal.

But like I said, 2011 is a completely different, much better Mumm-ra who I can see giving Skeletor a decent fight. 80's Mumm-ra is a literal curbstomp. Skeletor would... well the comic basically got it right, but there are many ways ahd Skeletor could easily think of several other ways.

Cheat

Hah, right.  That's like if Peter Griffin started calling himself the Fastest Man In the Universe because he beat Homer Simpson in a footrace.  Ram-man and Orko couldn't even pass tryouts for the Cleveland Browns.

I voted for Mumm-ra just because I don't think I could stomach agreeing with kirby007.

Dont worry this vote has been rigged already

Its coming home 

Please don't call He-Man idiotic. It's sad to see anyone defame 80s cartoons period, but when a Thundercats fan does it it just doesn't seem right. The 80s were and will always be the golden age of Saturday morning cartoons. Every one of them was amazing and deserves respect. Smurfs, GI Joe, Tail Spin, Gummi Bears, Silverhawks, Snorks...it just goes on and on. The irreverence of the Simpsons, Beavis and Butthead, of Ren and Stimpy, of South Park hadn't yetbegun and it was a wholesome time with great stories with wonderful messages behind each one. They taught us all to be better and to care about other people.

Those times are gone and scoffed at. Which is why I just can't have a Thundercats fan scoffing at He-man, or even She-Ra.

I'll give it to you that Mummra would probably win in a fight. Skeletor is a bit bumbling and is easily thwarted. But please, go easy on the whole crew. They mean well and they are powerful visions of a better past.

Well im not going to appologise im mentally still as young as when i first watched these shows. Forever young

Holy goodness.  I'm really curious as to what cartoons of that day he didn't find idiotic.  I'm guessing he had a Snarf plushie and still has it and rejects his love for all things Thundercat as a coping mechanism.  Well kirby?  Is is time to share?