Weldohnson was born on a whaling ship in 1979. When he's not trying to summon the Great Old Ones, he spends his time in squalid slums where alcohol helps him cope with his homesickness.

After graduating in plastic arts from the University of Paris-Sorbonne, he tried his hand at board game gamedesign with the trading card game Monstrures and the board game La Demeur En T.

After spending two years at Kino, an association promoting short films, as an actor, cameraman, story-boarder and puppeteer, Weldohnson works freelance, mainly as a story-boarder and illustrator, for video games and advertising. He also teaches comic-strip classes in elementary schools.

His first comic, White-Spirit, with Dédo on the script, was published by Delcourt in 2019. 

Others followed, notably on the networks (for Léon Blum's birthday at the PS; an appearance in Une Année Exemplaire by Lisa Mandel...), collectives (Axolot T5, Faire Face...).

In 2021, Steinkis released Harry Houdini, which Weldohnson draws. He is currently working on a number of cartoon projects, with werewolves and/or the climate as the backdrop.