Nintendo has posted an unusual and cryptic teaser video on its YouTube and social media channels, hinting at what seems to be a new horror project. VIDEO

The teaser features grainy footage of a figure in a trench coat with a paper bag over their head, displaying a drawn-on smiling face.

At the end of the video, Japanese text translates to "Smiling Man," while the accompanying text reads "#WhoIsEmio," with "Emio" being the Japanese pronunciation of "Smiling Man."

Nintendo fans quickly reacted to the bizarre teaser, which was released at 2 PM UK time.

"This is extremely weird and out of character for Nintendo," commented one user on the video game forum ResetEra. "The fact it's age-restricted and the whole tone of the video."

"Could it be a new Nintendo horror IP?" speculated another.

Some suggested it might be a strange viral marketing tactic for the Switch 2 (it isn't) or that Emio might be an unknown third Mario brother. (It's-a-me, Emio!)

Given the prominence of the teaser on Nintendo's official channels, it is likely an internal project, though Nintendo has rarely ventured into the horror genre. We have reached out to Nintendo for more details.