My absolutely disregard-canon take on Condiment King has somehow managed to become friends with Scarecrow what in the world (explanation under cut if anyone wants to hear my ramblings about my greasy rat nerd teenager Condiment King lol)
This poor man. This poor 17 year old chem nerd. Mitchell works the late shift at a fast food place after school, and it is the bane of his existence. The rude customers, the coworkers who hate him for no reason, the math test he knows he needs to study for tonight but there's literally nothing he can do because he has to run the stupid drive-thru window. And then, just when he thought this couldn't get any worse, Joker and Mad Hatter come bursting one night in to hold the place hostage because they're mad that the ice cream machine doesn't work. Seriously? The broken ice cream machine is grievance enough for supervillainy? If that's the case, Mitch has more than earned some of his own! After Batman comes to save the accursed restaurant, Mitch says that he'll close tonight, and when he's the last one in the building, he grabs condiment bottles and graffitis the whole place with them. He shoves more in his backpack, skulks out into the night, beelining for his school. He condiment-tags his math classroom, the cafeteria, the lockers, everywhere that irritates him. Then, he breaks into the chem lab. You know, there's some real nifty chemical compounds in ketchup and mustard he could mess with...
And thus, Condiment King was born! A very bitter, tired, at-his-limit teenage dorkus who screws around with condiments and chemistry kinda like that NileRed guy on YouTube, making all sorts of cartoon-science-logic substances and concoctions to do crime with! His costume is probably something clearly constructed from regular clothes, minimal sewing skills, and a dream, and he has a crown made of folded up to-go bags.
(Scarecrow finds out about this science geek, a social outcast, slighted by his peers and something relating to former employment, and he goes 'Gasp! Just like meeee!' and now Mitchell has a terrifying but well-intentioned supervillain uncle who will on rare occasion emerge from the shadows to see how his crimes are going and make sure he's, like, sleeping ever (Crane you hypocrite when was the last time you got 8 hours lol). One time he gave him a vial of fear toxin to use in his condiment weapons. That was a weird day for Batman.)