Mel

is one of Ben's rival scientists along with Flo. Because of his rivalry, they have done shady things.

Season 4
Mel appeared in Ben's Digital Detox walking with Flo in the streets. They notice Ben walking around and mocked him for being "kicked out of science." They then hear about the Squiggly Man Painting and plot to steal it to fund their research.

Mel broke in Tom's garage to steal the painting. They then find that Ben has set up traps all over the house to stop him. They fall for all the traps, but he was able to get his hands on the painting. Ben, however, sprayed water at him, causing his jetpack to malfunction and sent him flying out the door.