At the Marina Trench Airport, you'll find the Furious Artist cat (he's wearing a beret because of course he is) who wants you to make him stinky. He's on the first section of the map and will stand out because he's the only cat there.
Throw a bundle of money at him (which you can get from any ATM) by pressing the B button when you have it equipped to make him drop a can of spray paint and give you the achievement.