Alert immigration: Newly minted U.S. citizen Jim Carrey has a dark side.

"I like being the scary thing under the bed," Carrey says.

Good thing. The Canadian-born actor, who became a citizen last week so he could vote in November, plays evil Count Olaf in the film adaptation of the Gothic children's books "Lemony Snicket's A Series of Unfortunate Events." It opens today and is one of the holiday season's most highly anticipated movies.

"He's a sociopath," Carrey says in his first major interview about the role. "There's a bit more of an edge to this than the Grinch (whom Carrey famously portrayed in the 2000 film version). But the danger has to be real. If it isn't, the victories the kids have aren't real."

Carrey plays the guardian of the three Baudelaire orphans, who rely on their smarts to outwit the cruelly clever count, who is after their fortune.

The movie is based on the first three novels in the best-selling series by Daniel Handler, writing as Lemony Snicket. The 11th book in the series, "The Grim Grotto," is already a best seller.

Olaf's Dickensian persona appealed to Carrey. "As a kid I loved 'Oliver Twist' with Bill Sikes and all those wonderful characters. This has got a lot of that feeling, as well as being really funny."

Carrey also identifies with Olaf, an actor who leads a band of performers.

"I know this guy very well, this sort of acting guru," Carrey says. "When you meet his troupe, you realize just how insecure he is. They're just a collection of total freaks and losers. You can always tell a man by his disciples."

Carrey had a hand in fashioning the screenplay and then spun off from the page. "There were times in this movie where we went three days where I didn't say a word from the script."

Carrey said he likes how the kids are the most aware characters in the movie.

"The only intelligent ones in the whole story are the kids," Carrey says. "All the adults in these stories are completely inept, hypocritical and blind, deaf and dumb. They have no idea what's going on. The kids have to prove everything to adults in triplicate: They never believe them. So they're basically on their own. Which is true of life. How many children are out there who are put in the parent role early in their life? And kids have to say 'I'll take care of it. I'm 3, let me mix you a drink.' "

Carrey felt strongly about Olaf's physical characteristics. Hence the sightings of Carrey at awards shows bald as a cue ball. He also endured 3 hours of makeup and dropped 20 pounds.

"A couple of executives got kind of weirded out by my look. There was a lot of talk about it. But I believe there's nothing more neurotic than an actor losing his hair. So I sacrificed my own social standing and walked around like Nosferatu for several months."

Has his hair grown in differently? Cracks Carrey, "It grew back in flowers."