John Barrowman may be best known for his roles as Captain Jack Harkness and Malcolm Merlyn, but for one brief shining moment at Comic-Con International in San Diego, he was ... the Unbeatable Squirrel Girl.

And Harley Quinn. Oh, and Zapp Brannigan from "Futurama."

In short, the actor/singer/author was a quick-change artist Friday night as he hosted the 2016 Eisner Awards, shifting from costume to costume to costume.

As you can see from the photos below, Barrowman can rock a too-short military tunic or a bushy tail with equal ease.

Introducing Matt Groening in style @Comic_Con #EisnerAwards #SDCC #lovespanx #cosplay #jbstyle pic.twitter.com/Az21mOfOCi- John Barrowman MBE (@Team_Barrowman) July 23, 2016

Yes Squirrel Girl happened @Comic_Con #SDCC #EisnerAwards #cosplay #jbstyle JB pic.twitter.com/mLb4s9FY1I- John Barrowman MBE (@Team_Barrowman) July 23, 2016

.@Team_Barrowman's next number at the Eisner Awards? It's Harley Quinn of course, puddin'. pic.twitter.com/bY0DcGhvZQ- Comic-Con HQ (@ComicConHQ) July 23, 2016