Ghost of Christmas Past  was one of the ghosts in The Real Ghostbusters in episode "Xmas Marks the Spot". While not much is known about her, she is well spoken when she speaks and is also aware of events.
The Real GhostbustersEdit
The Ghost of Christmas Past is the only female member of a trio of entities who are most famous for showing Ebenezer Scrooge the error of his greedy ways during the Christmas holiday. She selects the memory in which a person is most carefree and innocent to serve as a tool for comparison with their adult life. However, the time lost Ghostbusters accidentally trapped the trio and stored them into the Containment Unit, thus altering history.  The Ghostbusters impersonated the three ghosts while Egon Spengler extracted them from the Unit and helping restore the timeline to its proper form. Peter Venkman impersonated her until she and the other ghosts were released.
When the Ghost of Christmas Present possessed Woodrow Wainwright Fraser III, Past and Future visited him for several years in an attempt to convince him to return to them and carry on his duty. Finally, on one Christmas Eve, Fraser/Present hired the Ghostbusters to trap the two ghosts. The Ghost of Christmas Past teleported everyone several decades into the past to Camp Waconda, where a young Ray Stantz was roasting Stay Puft Marshmallows with his parents. The Ghostbusters elected to trap her and move onto the next ghost. After Peter realizes the Ghost of Christmas Present was possessing Fraser, he wrangled Fraser free and the Ghost of Christmas Past is also freed and reunited with her two comrades.
She spoke a little during the episode, and what is gathered is she is intelligent and aware of current events.
The P.K.E. Meter registered the three ghosts as big and powerful. 
- The Ghost of Christmas Past is referenced by Eduardo Rivera. 
- On page 12 of Ghostbusters Issue #16, the Ghost of Christmas Future makes a non-canon cameo as one of the portraits on the wall.
- ↑ Winston Zeddemore (2009). The Real Ghostbusters - "Xmas Marks the Spot" (1986) (DVD ts. 09:52-09:56). Time Life Entertainment. Winston says: "Then those ghosts we trapped, they must've been the Ghost of Christmas Past, Present, and Future."
- ↑ Female Civilian (2009). The Real Ghostbusters - "Xmas Marks the Spot" (1986) (DVD ts. 10:00-10:04). Time Life Entertainment. Civilian says: "In 1837, Scrooge defeated the three Christmas Ghosts all by himself."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Xmas Marks the Spot" (1986) (DVD ts. 04:39-04:44). Time Life Entertainment. Egon says: "I'm picking up other presences. Big. Powerful. They're coming in at 12 o'clock high."
- ↑ Eduardo Rivera (1997). Extreme Ghostbusters- Ghost Apocalyptic Future (1997) (DVD ts. 06:16-06:19). Sony Pictures Home Entertainment. Eduardo says: "You mean like the Ghost of Christmas Past and Future?"