Jim Carrey, Jenny McCarthy and her son Evan
03/10/2008 AT 03:20 PM EDT
Jim Carrey has been scoring points with Jenny McCarthy's 5-year-old son, Evan – with his role as the voice of the lead character in Dr. Seuss's Horton Hears a Who.
"I think he thinks I'm pretty cool anyway," Carrey, 46, told PEOPLE on the red carpet at the movie's Los Angeles premiere over the weekend. "It's pretty great. I've been reading [How the Grinch Stole Christmas] to him forever, and he wasn't aware that I was actually the Grinch" – Carrey's role in the 2002 movie.
But Evan has figured out Carrey's latest role, in Horton. "This one he clued into. We took a walk around today, and he said, 'You know, you're Horton. You're in the movie. You did the voice.' As if I needed to know that information," said Carrey, who also brought his daughter Jane, 20, to the premiere. "It was cool."