Are they real tats or just part of his costume to look more like a legitimate Fed? Asking for a fren. They look fake.

I think it's a Nordic/viking symbol.

Edit: what I got from a quick Brave search actually makes sense:

"It is believed to represent fertility and rebirth, as well as the power of Viking practitioners and shamanists who were said to be able control people’s minds and bind their fates."

Hence his nickname and viking horns.

That's a viking valknut symbol