NHL Star Taylor Hall -- GNARLIEST Hockey Injury Revealed in Photo

NHL superstar Taylor Hall is lucky to be alive after an ice skate ripped his skull open -- and his team just tweeted the first photo of the nasty ... NASTY aftermath.

The Edmonton Oilers star forward suffered a Frankenstein-like gash Tuesday night when he fell during warmups, and collided with a teammate who couldn't avoid slamming his skate on Hall's head. He needed 30 stitches to stop the bleeding!

Hall -- who's been out of the lineup since the injury -- was not wearing a helmet at the time of the accident. NHL players are required to wear helmets during games, but not warmups.

The Oilers are now advising their players to wear helmets -- while other teams are making it mandatory.