There was Taro Tsujimoto.
On May 28th, 1974... the Buffalo Sabres selected Tsujimoto in the 11th round of the NHL Amateur Draft. However he never suited up for the Sabres that season, because he didn't exist.
He was a fictitious hockey player who played in the Japanese Hockey League on a fictitious hockey team (Tokyo Katanas).
Luckily for cardboard collectors, his hockey card isn't fictional. Panini produced a card of Tsujimoto for its 2010-11 Score Rookies & Traded set. They've actually held their value due to Panini's decision to limit the card's production (inserted into one out of every twenty factory sets).
I've wanted one of these since they came out, but wasn't willing to pay the ridiculous prices for a fictitious hockey player. Last month, I picked one up off of eBay for $9.05 (+ $3 shipping).
Thank you Mr. Imlach (Buffalo's general manager at the time)! Without your prank, there would be no Tsujimoto hockey card and I'd be $12.05 richer.
Happy Tuesday and sayonara!