Wrexham have had a number of celebrities turn up at the Racecourse Ground after Ryan Reynolds and Rob McElhenney's takeover of the club.
Ferrell, who co-starred with Reynolds in the Apple TV musical Spirited, was one such celeb, and Mullin almost bumped into him leaving the lavatory.
Still, Mullin, who has become a cult hero in the football world with his goalscoring exploits at Wrexham, says that the players are now more than used to A-listers heading to their corner of Wales.
Speaking in the latest episode of GOAL's Box to Box series, Mullin said: "Last season I came out of the toilet and Will Ferrell is just stood in the changing room. I wasn’t expecting that, that was a bit mad. Now, it’s like: ‘so and so is coming in this week’ and we’re like ‘oh that’s sound, no problem’."
Reynolds is perhaps best known in Hollywood for his role as the wise-cracking superhero Deadpool, and with Deadpool 3 on the horizon, Mullin admits that he would jump at the chance to work with the owner on camera.
He added: "I’m pretty sure we’d all jump at the opportunity. It would be phenomenal. I don’t know whether I’d suit it or whether I’d be my own superhero."
Of course, Wrexham's promotion from the National League to League Two sparked wild celebrations, with the players jetting to Las Vegas for a major party.
Mullin, though, maintains the trip was not nearly as crazy as supporters might have imagined.
He said: "It was really quiet. We just sat by the pool, not much really happened. It was quite subdued. It was incredible. For the owners to treat us the way they did in Las Vegas was phenomenal.
"We were walking into a nightclub and Steve Aoki was playing a set and he stops the set to welcome us in and he’s playing our fans singing my song. And I’m like: ‘wow, this is mindblowing!’."
Check out the full Paul Mullin episode of Box to Box on the GOAL YouTube channel.
