Locusta

Locusta is an Assassin-class Servant summoned by Ritsuka Fujimaru in the Grand Orders of Fate/Grand Order. A notorious poison maker of Ancient Rome and a favorite of the Emperor Nero. She was discovered by Nero's mother, Agrippina, and is said to have created the poison that she used to kill Emperor Claudius as well as participated in Nero's assassination of her stepbrother Britannicus. She also taught Nero's other poisoners. After Nero's death, she was executed along with Nero's other favorites by her successor, Galba. An excessively high-strung oddball. Weirdly fixated on mushrooms. She adores Nero and tends to also like Nero's supporters. She has an overblown distaste for some people but in general, her personality is fun and cheerful. However, due to her loose screws, she can offer people poison with no ill intent whatsoever.