The Mortal Kombat reboot trailer hints that the upcoming movie might include Animalities as well as bloody Fatalities. The nostalgic, violent teaser promises that the video game series' legendary finishing moves will take center-stage with a surprisingly accurate take on some of the most iconic combat moves. From the look of the first extended Mortal Kombat footage, the gore on show is earning the R-Rating the reboot has always unashamedly aimed for and there's one moment, in particular, that stands out.
Right at the end of the trailer, Kano pulls off his Heart Rip Fatality, announcing himself the winner in a moment that perfectly balances the Mortal Kombat reboot's campy/gruesome tone. But the identity of his opponent is the trailer's biggest headscratcher. From its almost lizard-like appearance, there is the possibility that the reboot's secret character is in fact legendary Mortal Kombat character Reptile, which would fit that character's mythology. It would be a radical redesign, but that isn't entirely unprecedented, particularly if the film-makers are protecting it as a secret.
Then again, the answer could also be this universe's take on something Mortal Komat: Annihilation got horribly wrong: Animalities. On top of Fatalities, Brutalities, Babalities, and Friendships, animalities are part of the games' dense lore on how bouts can end. Added to Mortal Kombat III after a fan rumor that Sub-Zero could turn into a polar bear for a finisher, they offer players the chance to transform into chimpanzees, kangaroos, T. Rexes, skeletal rhinos, and a host of other creatures. The fact that a humanoid reptile seems to exist in the trailer might be evidence that Mortal Kombat has reinvented Animalities as yet more fan service.
Strictly speaking, Liu Kang's Dragon's Bite was the original Animality even before the Mortal Kombat series adopted them in Mortal Kombat III. Later renamed The Beast Within, it originally showed Kang himself transforming into a dragon and biting his victim in half. In MKX Mobile and Mortal Kombat 11, it then transformed into Kang manifesting a fire dragon as he does in the trailer for Mortal Kombat's reboot. In Mortal Kombat: Annihilation, Kang transforms into his Animality form having been taught the power by Nightwolf, and the poor CGI involved made it one of the movie's most notorious low-points. Changing the logic for the reboot to fit the later games makes sense even if it means his finisher is not a true Animality. And that doesn't necessarily mean they're not possible in the reboot as the reptilian creature suggests.
While Outworld's characters are more supernatural from the trailer's reveals, the other realms of the Mortal Kombat universe are generally populated by basically human-like figures. There are more animal-like humanoids, like Moloch, Motaro the centaur and of course Goro, the Shokan who is glimpsed in the trailer, but the closest approximation to the reptilian in the trailer is the Saurian race, of which Reptile is a member. His devolved form actually resembles the reptile in the trailer and while his Animality from Mortal Kombat III was a chimpanzee form (somewhat illogically), having him able to transform into the more dinosaur like form of his ancestors makes a lot of sense. That would be a significantly better way of incorporating Animalities into Mortal Kombat than Annihilation managed and may just explain the strange reptile mystery of the trailer.