Okay, Mumm Mutt, I remember, but Enflamer? Mumm Rana? Wiz Ra? When did these guys show up? The last few episodes I remember introduced a few new Thundercats, as well as the ghost of an evil one that was quite a badass (I’ve still got his figure, the friggin’ snaggletooth), but I don’t recall any of these other guys. And can you give a little rundown on how Mumm Ra met his end?
Wiz Ra - As I said AFAIK appeared in only one episode.
Enflamer- AFAIK He was only in two episodes. The one in which he reforges the broken Sword Of Omens, and part five of the Anointment Trials. He appears in that for about 10 seconds. Lion O submerses him in water, extinguishing his flame.
Mumm Rana- She was a regular character for a while.
The New Thundercats- Naturally, I could just Google, but I feel that would be cheating. Lynxot, Pumyra and Bengali (Bengali is the same subspecies as Tygra, but his coloration is pale blue and white. Tygra does call him brother at one point, but seems to be speaking figuratively) were introduced in a direct to video film. They lived not in the Cats’ Lair, but in the Tower Of Omens.
At some point, they also introduced the Book Of Omens and the Key Of Omens. IIRC the Book was a mystic tome of Thunderan history and knowledge. It could be entered by using the Sword of Omens or by manipulating parts of the Book in proper sequence to expose the lock, then opened with the Key.
The Anointment Trials
Non Spoiler- One morning, Lion O wakes to find everybody but Snarf is gone. Snarf tells him that although he is heir to the throne, Lion O must pass a series of tests called the Anointment Trials before he can be crowned king. He must prove he is stronger than Panthro, faster than Cheetara, trickier than the Thunderkittens, able to seperate reality from an illusion casting power Tygra has (but has never used or mention before this), and for the final test Lion O must go forth alone and destroy evil. IIRC he is not allowed to use the sword or the claw shield during the trials.
After passing the other tests, Lion O heads for Mumm Ra’s tomb
He attempts to sneak in via an underground river. Mumm Ra detects him immediately and alerts the various monsters guarding the river. Lion O makes it past them and faces Mumm Ra in single combat. Lion O is unable to harm Mumm Ra. Then, he accidentally damages Mumm Ra’s stone sarcophagus. This causes Mumm Ra pain and seems to weaken him slightly. Liono proceeds to bash the sarcophagus into small pieces. Mumm Ra screams in pain and gets weaker and weaker. Eventually, he loses enough power that he spontaneously transforms from the musclebound battle form back to shrivelled mummy. He begs Lion O to spare his life. Lion O instead destroys the sarcophagus by lifting it over his head and hurling it onto the floor. Mumm Ra screams, shrivels, and turns into a pile of dust.
IIRC There was a season which seemed to take place after the Trials. There were new villians (The Luna tiks IIRC) and Tygra and Bengali occasionally used their species illusionar powers. However, again IIRC there were also episodes made after the trials which seemed to ignore them. This may have been due to a screw up in syndication.
I just watched the episode where Lion-O defeats Mumm-Ra and Mumm-Ra was clearly shown to have survived at the end of the episode, even though he turned to dust and blew away. I recall that in the next season, when he made his big re-appearance, he wasn’t repelled by his reflection anymore.
Do not ask me how I got the episode, it was via a method That Shall Not Be Named on the SDMB.
Now that is freakin’ awesome! I can’t believe the boys in my neighborhood never had that one! Gross, but very cool.
I remember the episodes dealing with The Anointment Trials. His battle with Panthro is where I learned how to play Mercy 
Still, I didn’t think that was the end of Mumm Ra…I also recall a season after that and could have sworn the greenish-blue bastard showed up in that. And I still have no recollection of Mumm Rana or Wiz Ra. Is the whole series out on video yet?