Fink is a short green humanoid rat. She has lime green fur and long messy mint green hair. She has small ears and a long tail coming from her dress. Her scleras are light red, and she has two eyelashes on each eye. She also has a notable sharp snaggle tooth on the right side of her mouth. She wears a white lab coat with a skirt, a pair of magenta gloves, and dark gray boots.
Fink is a young mouse with an aggressive attitude as she tends to rough up anyone in her way and insults anyone. She also enjoys mayhem and destruction. Much like her master, Professor Venomous, she enjoys fighting heroes. She is also very attached to her boss. It is revealed in "Villains' Night In" that this is because he treats her well, giving her praise and gifts much like she is his own child. She mentions that she is his favorite minion.
She does not get along well with the robots of Boxmore, as she is very free spirited and malicious, and doesn't want to play by their rules.
Aside from her malicious nature, her personality is comparable to that of a young child. This is made clear in "Villains' Night In" when after falling asleep, she is cradled in Professor Venomous' arms, and he mentions her previous babysitters.
- Special Collar: She wears a collar given to her by Professor Venomous, that has a little opening, and if a glorb is inserted in it, she gains great power for a limited time. Her gloves and boots go purplish-black, and lavender spike bracelets and collar appear on her, while her eyelids go dark indigo. Her hair also appears to be more wild. In this form, she gets very strong and can float. This form is similar to T.K.O.
- "Boxmore Infomercial" (debut)
- It was confirmed by Ryann Shannon that she did get ice cream from Professor Venomous in "Boxmore Infomercial".
- She was designed by Ryann Shannon.
- Her name and design might be a reference to the Rat Fink character, like her green fur and bloodshot eyes.
- She looks similar to Panini from Chowder.
- She owns a cell phone which she uses to communicate with Professor Venomous when they're apart. His number is named "The Boss" on her phone.
- While using a glorb on her collar, she gets an appearance similar to TKO.
- Interestingly, the model sheet for this form of Fink, is named "Turbo Fink".