05/28/2013 AT 03:05 PM EDT
It was a pretty cool night for a 5-year-old.
Grant Holmquist, – the blue-eyed, chubby-cheeked Hangover
baby who reprises his role
of Tyler (a.k.a. Carlos) in The Hangover Part III
– got to walk the red carpet with his costars in Hollywood last week. And it seems that they're just as taken with the little guy as moviegoers.
On set, "Zach [Galifianakis] did an amazing job loosening Grant up," the little actor's mom, Carrie Holmquist
(who was on hand to snap photos), told PEOPLE. And Grant was clearly delighted to see "Zachy," as he calls him, on the red carpet for the premiere. (Grant only walked the carpet, he wasn't allowed at the R-rated screening since he's a minor.)
In addition to Galifianakis, Bradley Cooper
(who endearingly got down on Grant's level at the premiere) and Ed Helms also made their young costar feel most welcome while filming, Carrie added.
"There were toys all over the place and they were pretending a stuffed dog was attacking them," she says. "They were throwing it back and forth, just making Grant laugh."
Director Todd Phillips "was great, he was really hands on with Grant and very patient," adds Carrie. When Grant was re-cast in the role for the third movie, "He treated us like family and was very excited to see us as we were to see him."
And Heather Graham, who plays Grant's mom in the movie, "was really sweet and Grant took to her as well," says Carrie. We'd say so, judging by the sweet photos of him holding Graham's hand for photos at the premiere.
Nicely done, little man.