When Thor and Korg are at the weapons rack preparing to for Thor's fight against the Grandmaster's champion we have the following scene. In it Korg offers up a "big wooden fork" as a weapon to use but both of them quickly dismiss it.
INT. THE ARENA - RECEIVING AREA 40
Thor, Korg, and a gaggle of other prisoners/fighters have been led from their cells to a PRE-FIGHT HOLDING AREA.
Korg and Thor are by the weapons rack.
Korg: Yuck! There’s Still someone’s hair and blood all over this. Guys, can you clean up the weapons once you finish your fight? Disgusting slobs.
(then:) Thor...wanna use a big wooden fork?
Korg: Yeah, not really useful unless you’re fighting off three vampires that were huddled together.
Thor: Ragnarok official script
Inverse and various other sources such as reddit theorise that this is a reference to What We Do in the Shadows. This is because Taika Waititi directs both, plays Korg and one of the vampires in the latter.
However, is there a comment anywhere from Waititi confirming that this is the reference or is this a reference to something else?