In the 1998 film, Elsie is first seen on screen briefing Dr. Nick Tatopoulos on the situation. She is convinced that Nick is not the correct person to be investigating Zilla, and she is to some extent correct. Throughout the film she works with the American military to try and find a weakness in the creature. She is highly cynical and sarcastic.
Elsie is first seen in episode 1 of the show, which begins during the events of the film from earlier that year. She is called in to scan for electrical activity in Madison Square Garden, where Zilla made his nest. After this, soldiers come into the tent she and Mendel Craven had used to perform research in and begin to confiscate their findings. Elsie is upset by this, and Nick Tatopoulos shows her and Craven his research facilities, and introduces them to Randy Hernandez. She then becomes a valuable member of H.E.A.T.. Throughout the series, Elsie develops a rivalry with Nick's girlfriend Audrey Timmonds, who accuses her of trying to take Tatopoulos' affections away from her. Whenever Timmonds makes such accusations Elsie always scoffs at them.
- Elsie Chapman is a firm believer in the existence of Alien life.
- Elsie looks significantly different in the animated show from her movie version: she has no glasses, her hair is straight instead of curly, and she usually wears a green sweater instead of the jacket as in the film.
- She and Craven appear to be in a relationship.
- She shows some interest in Nick, which ends up having a jealousy issue with Audrey.