The Pretzel Thief is a submission made by u/maxwell_paranormal on Reddit's copypasta subreddit. The submission tells the story of how if you witness any paranormal activity it could be "The Pretzel Thief", using an elaborate scheme to capture and eat pretzels. In the text it explains what the pretzel thief looks like:

It looks like a very skinny man in a black suit with grey gloves as well as thin boney fingers and a horse mask. It can cling to walls easily so it crawls around like a spider. so like just beware if u have a scary wary paranormal incident or something it could be the pretzal theif.

The submission also includes a link that goes to a poorly drawn image of "The Pretzel Thief", likely drawn in MS paint.

link to image

The submission says that The Pretzel Thief travels the world searching for pretzels 24/7, thirsty for the wonderful sensation of consuming pretzels.

The copypasta seems to have been inspired by one of maxwell_paranormal's past comments on /r/paranormal, which says

it might be the pretzel thief I heard he has become invisible this time around o_0

link to comment

The copypasta is bizarre and genZ humor, but its still a copypasta.