Lieutenant Helga Katrina Sinclair is the secondary antagonist who later reformed in the 2001 film, Atlantis: The Lost Empire. She serves as second-in-command of the expedition to find the lost continent of Atlantis. She also serves as the personal assistant to Preston B. Whitmore.
- She played The Queen of Hearts in Rukia in Wonderland
- She played Zam Wessel in Star Wars (160 Movies Style)
- She played Ursula in The Little Mer-Chinese Woman
- She played Shenzi in The Rodeo Cowboy King
- She played Queen Fuil in Astro The Island Super All Stars
- She played Grand Councilwoman in Sakura and Mushu
- She played Runt Mama in Nathan Little (Chicken Little)
- She played Constance Nebbercracker in Monster House (Dragon Rockz Style)
- She played Niko's Mother in Despicable Me 3 (Dragon Rockz Style)
- She played Aunt Sponge in Hiro and the Giant Peach
- In Atlantis: The Lost Empire (399Movies Style) she is played by Mahra.
- In Atlantis (Dragon Rockz Style): The Lost Empire she is played by Azula.
- In Atlantis: The Lost Empire (Good or Evil Style) she is played by Elsa
- In Atlantis: The Lost Empire (HarryDR19 Style) she is played by Maleficent.
- In Atlantis: The Lost Empire (Jonah Campbell Style) she is played by Gladys Sharp