This hobbie is stranger than anything you can imagine. Imagine a hobbie which started out as a brutal prank on someone. Then turning this into a hobbie. I will go into more detail if anyone wants to hear about it. But imagine someone, waiting excitedly to find a dead animal, road kill basically, even looking for road kill, every week. Picking it up and driving somewhere, like the beach late at night. Swimming out to a boat with it tide around your ankle, then putting it on a boat. Then swimming back. Waiting for the reaction on local social media forums. Then repeating this in different and weirder places.
This isn't a sick joke by the way. The guy who I know who does this, (with another friend of his), genuinely feel happy about it.