Russell Crowe Explains That Wild Bloody Birthday Video

Actor Russell Crowe had a bloody good time with a prank he once pulled on filmmaker Ron Howard during the production of “Cinderella Man.”

In the 2004 clip shared on Twitter last week, Crowe boasts of recovering from shoulder surgery ― but as he speaks, blood gushes from his shoulder.

“While training for Cinderella Man I experienced a subluxation of my left shoulder which required surgery,” Crowe wrote as he retweeted the video. “I knew that Ron Howard and the studio were concerned so I thought I’d send a video to relax them.”

Warren Beaton, a special effects artist on the “Lord of the Rings” films, created the effect for Crowe. He wrote on Twitter that it was “the BEST fun Special Effects morning EVER!” and compared it to something out of a Monty Python skit.

He added in a follow-up tweet:

Crowe said he was “back in the ring” just three weeks later, presumably without the blood.

“Cinderella Man” is part of internet lore in another way: Crowe sold off memorabilia, including a jock strap he wore in the film, during his 2018 “divorce auction.”

That jock strap was among the items won by “Last Week Tonight” host John Oliver, who donated them for display in what at the time was one of only a few Blockbuster video stores left.

When that one shut down, Crowe got his jockstrap back ... probably:

This article originally appeared on HuffPost and has been updated.