Battlestar Pegasus is a fictional spacecraft that appears in the both the original

Battlestar Galactica (1978 TV series)

Battlestar Galactica is an American science fiction television series, created by Glen A. Larson. It starred Lorne Greene, Richard Hatch and Dirk Benedict and ran for one season in 1978–79. After cancellation, its story was continued in 1980 as Galactica 1980 with Adama, Lieutenant Boomer and...

 and the reimagined television series Battlestar Galactica.
Battlestar Pegasus appears in the original series two-part episode, "The Living Legend

The Living Legend

"The Living Legend" is a two-part episode of the original Battlestar Galactica television series. The episode is often rated as one of the most popular of the original series...

".

Pegasus spent her earlier life patrolling the edges of Colonial space under Commander Cain

Commander Cain

Commander Cain is a fictional character in the original Battlestar Galactica science fiction TV series, portrayed by the American actor Lloyd Bridges.-Description:...

, a renowned (and later legendary) Colonial warrior. Later, Pegasus took part in the battle of Jol'Trata in which she was badly damaged.