The black eye and bloody mouth will fade ... but Jake Paul was still able to get a permanent reminder of his altercation with Floyd Mayweather -- immortalizing the incident with a new tattoo!!
The YouTube superstar showed off his new ink Thursday night -- just hours after he was roughed up at Hard Rock Stadium by Floyd and the boxer's bodyguards ... and it's pretty damn funny.
The tat -- located just below his right knee -- reads "Gotcha Hat" and features a picture of a baseball cap.