You may know her from the 9NEWS show Gidget the sea lion show with your host Drew Soicher.
She predicted the winner of Denver Broncos games with Drew for six years. Her last show was in 2010.
Gidget was 27 years old and had arthritis.
The Denver Zoo put her down Wednesday night because she was in too much pain.
This is not the first death the Denver Zoo has suffered this year. On March 14, Soosha the polar bear died. Bismarck, a disabled sea lion, died during surgery in August. Mimi the elephant died on Oct. 9.