The somewhat absent-minded and unethical yet very beautiful head of S.H.U.S.H.'s research division, Dr. Sarah Bellum is somehow both profoundly intelligent and mind-numbingly stupid at the same time (She seems to have a bi-polar disorder of some sort). Her goal is to win the Nobel Prize with the inventions she creates for S.H.U.S.H., which have included the Norma Ray and Expando-Whammo Pies. She shows a cheery disregard for any professional ethics, mentioning off-handedly in both "Heavy Mental" and "Disguise the Limit" that her experiments tend to kill the test subjects; in "Mental", the risk of harm was so big that she wanted "vic- er, volunteers" that weren't covered by S.H.U.S.H.'s medical insurance. When unable to tell the difference between Darkwing and a disguised Negaduck in "Just Us Justice Ducks", she happily announced that she'd just kill them both to save time,
In the "Paraducks" alternate timeline where a young Drake Mallard didn't meet a time-travelling Darkwing Duck, Sarah Bellum merely works as a mechanic.
Dr. Bellum is one of several Darkwing Duck characters who appeared only during the Fall run of the syndicated season of the series and then dropped completely out of sight as the writers of the show began focusing less on Darkwing's dealing with SHUSH and more on his battles with St. Canard's various supervillains. Like many characters her introductory episode ("Heavy Mental", 17th in production order) was aired long after she had made several appearences on the show.