Karai is one of the bosses in the Teenage Mutant Ninja Turtles: Out of the Shadows-video game. Her design is based on a more grown-up version of her cartoon version in the 2012 series. She also appears in the 2013 video game, but is not fought against at any point. She also appears in Danger of the Ooze where she is held captive by Shredder.
Both Karai's human form and her snake mutation are playable in Teenage Mutant Ninja Turtles Legends.
TMNT Legends Bio
Karai is rebellious, anti-authoritarian, and driven. Shredder trained her to become one off the toughest ninjas in Japan. She's confident and shares a special affinity with Leonardo, seeing the heroic leader underneath the shell.
More animal than human, Karai-Serpent's rage controls her. It's very hard to reason with her, but there are moments when she recognizes the Turtles. She has some memories of her past and can return to human-like form, but not for long.