They're from an anime, Chainsaw Man. Haven't watched idk why they have sharp teeth, but my best guess is that it's an anime where they use their OP chainsaw teeth to make a killing in the lumber industry, that's definitely what it's about.

[–] SchmallChild@sh.itjust.works 4 points 2 years ago

I watched the anime, your guess is right.

[–] Kolanaki@yiffit.net 4 points 2 years ago

They have sharp teeth to show they are demons, I thought. The main dude doesn't have sharp.teeth until he is made into a demon when his little chainsaw dog replaced his heart.

Others have pointed out there is inconsistencies with this, though. I just figured they were oversights in production and the sharp teeth are still intended to represent when the character is demonic.