There is some controversy over the proper spelling of some of the lesser known names and places in the Mortal Kombat universe - most notably from the cartoon show, Defenders of the Realm. I have assembled here a list of some of them as well as various sources, which mostly include closed captioning from a recording of the show and screenshotted here.
Goro's Brother Durok/Duroc
Perhaps one of the most popular "non-canon" characters in MK's history, the Animated Video stated that Goro killed his older brother over who could present their father with a rare gift. Killing his brother also enabled him to become the Prince of the Shokan. According to the closed captioning, the brother is named Duroc. However, a rare CD soundtrack for the animated video that was for "promotional use only" listed him as Durok:
Jeweled Nika Egg
What was the gift that Goro and his brother were fighting over, anyway? It was a rare and precious Jeweled Nika Egg, which they both wished to present to their father King Gorbak (who was overall, pretty pleased to see that Goro had become so ruthless that he killed his brother).
According to the Defenders of the Realm cartoon, the leader of the Lin Kuei clan (and the one who came up with the idea for automation) was named Oniro. Interestingly enough, when the MK games a couple years later decided to introduce their own canon version of the Lin Kuei grandmaster, he was never named and looked very different from Oniro:
Komodai was also featured on Defenders of the Realm, he was raptors of Reptile's race. What's also interesting is that Jax mentions that he thought Reptile's race was extinct, indicating that Komodai and Reptile are definitely not one and the same.
The tape that this came from was too old to be read by a standard closed caption reader, but luckily my TV Tuner card's built-in closed captioning software was able to read it. (This is why this screen capture looks different than the others.)
Karbrac is the new leader of the nomads! One question – who was the old leader? It could have been Baraka or possibly even Goro (who was shown to be the leader in the Animated Video) but it was never stated in DOTR.
Another character from Defenders of the Realm, Ruby, was very similar to the character Tanya in that she was friends with Kitana, came from a realm that Shao Kahn had invaded, and was notorious for being a traitor, selling out her allies to the likes of Shao Kahn. Unlike Tanya, instead of coming from Edenia, she is from another realm called Hinpar:
One of the many realms that the mortals would travel to in DOTR ended up being Xaa. Like Outworld, Raiden's powerless there.
Another realm they travelled to was Zaterra. When the earthlings were exposed to the "Gem of Tetsurri", their souls were darkened and they nearly destroyed each other. It was explained that it wasn't a gem at all, but rather a crystallized heart that belonged to Zaterra's tyrant ruler, Tetsurri.