Shirts That Go Hard

Just straight up not being too serious about themselves while still being serious in the act I would recommend Alestorm, Brothers of Metal and Nanowar of Steel. The last one describes thenselves as Humor Metal. Very skilled musicians doing metal of various mainstream genres. Like Norwegian Reggaeton, heavy metal reggaeton about norwegian black metal.

If you go into power metal I can also recommend Gloryhammer (fantasy in space by the frontman from Alestorm), Grailknights (early 90's action figures, check out Pumping Iron Power for a great workout track) ang Wind Rose (dwarf metal with a great cover of Diggy Diggy Hole and just released Rock and Stone). Power Metal in general is just filled with thematic bands. Final recommendation would be Power Wolf (gothic symphonic metal, "catholic werewolves").

Okay, there are: Feuerschwanz (Fire tail/dick) for German funny medieval metal with songs like "Metnotstand I'm Märchenland" (Mead-shortage in fairyland) or "Dumme Frage, Saufgelage" (stupid question, booze-session) Alestorm for a pirate-y metal with song like "Mexico" (the title isn't a pun, but the song is funny) or "Zombies ate my pirate ship" Korpiklaani for the purest of drunken metal with songs to a lot of alcoholics including "Vodka", "Tequila", "Beer Beer" and more...

I can also recommend Electric Callboy, but they're Electronicore (= electropop + metalcore) rather than folk. "We Got The Moves" has become quite the hit as far as I can tell. Do make sure to watch the video because it really sells the point.

Who is the Bloodhound Gang of folk metal?

First that comes to mind is Feuerschwanz: https://youtu.be/jWXsSwAMSHA