It's a parody of overserious memes that are trying to sound edgy and badass. The archetype is a gun-wielding skeleton that's riding a motorcycle and saying something about thin blue lines, but wolves and other imagery are also adjacent.
Instead, THE_PACK takes that aesthetic, cranks it up to 12, and adds some silly text. Everyone is role-playing as a skeleton that's obsessed with motorcycles (hogs). You have to TALK IN ALL CAPS to be heard over the engine noise. And everyone's friendly and welcoming in a way that edgelords aren't.
When I was in early 20's it was much easier for me to chat with people much older than me than ones of my age, unless they shared my hobbies and interests.
Now in my late 20's, I still find chatting with people of early 30's easier, but I think that's reasonable.