Roy Halladay enjoyed his retirement by going to an '80s costume party. Most people go to '80s parties in the typical '80s gear -- tight neon clothes, hairbands, etc. -- so what better to represent the 1980s than a guy you played with in 2010?

@kmo50Moyer Fallin in love with 1986 #49 @Cubs thanks Roy and Brandi for the tribute #80scostume pic.twitter.com/yb0Oi7gBmC — Jamie Moyer (@jmo50Moyer) December 30, 2013

Moyer, of course, played in the majors from 1986 until 2012, when he pitched his last ball for the Rockies at the age of 49. Unbeknownst to us, Halladay was on the tail end of his career when the two played together in 2010, but he had been just 9 when Moyer made his debut for the Cubs in 1986. This picture was tweeted by Jamie's wife -- that's her making the heart gesture, right? -- so we're guessing Doc had Jamie's blessing.

H/T to MLB Fan Cave for finding this, and also finding Ryan Howard and Jimmy Rollins' costumes: