Some people seem to turn Halloween into a mega-experience — big parties, big costumes, big times. Then there’s Seth Rogen. For him, the holiday just meant lots of chocolate and television.

“I had a lot of allergies when I was a kid and I couldn’t eat sugar very often,” Rogen recalled. “So for me, Halloween was just a day to gorge myself.

He also savored ABC’s Friday comedies “because I was a nerd and had nothing to do on Friday nights. Their Halloween episodes … always spawned some good comedy.”

So it’s logical that Rogen is now a star of the newest Halloween special, “Monsters vs. Aliens: Mutant Pumpkins From Outer Space.” It’s in a week stuffed with Halloween shows.

How stuffed? Well, at 8 p.m. today, two cartoons collide, with “Monsters” on NBC and Charlie Brown on ABC. Both shows run twice this year — ABC’s ran on Tuesday and repeats today, NBC’s at 8 p.m. and 8:30 p.m. today. And cable counters with piles of Halloween movies. All of this makes sense to Rogen, who seems less excited about the costumes-and-parties part.

“I have a girlfriend now and I’ve entered the unfortunate world of paired costuming,” he said. “I always end up being the lamer half …. like she’s a dog and I’m a fire hydrant.”

More often, he’s busy doing or watching comedy; voice work fits neatly. “I like to work a lot and one thing with animation is they can really schedule it around you.”

He’s been working for more than half his 27 years, thanks to liberal parents in Vancouver. “I started doing stand-up (comedy) when I was 13,” Rogen said. “My mom would drive me to all the shows and not be upset when I had to miss school the next day.”

Straight from high school, he went to Hollywood and landed supporting roles in two TV series — “Freaks and Geeks” and “Undeclared” — produced by Judd Apatow. Then came Apatow movies — “The 40-Year-Old Virgin,” “Knocked Up,” “Superbad,” “Pineapple Express,” “Step Brothers,” “Funny People” — and some writing. Now Rogen is busy on “The Green Hornet” (as producer, writer and star), while squeezing in animated work on the side.

He liked cartoon movies as a kid, but they seemed “more female-skewed.” Then he saw “Shrek” and was a fan. “It seemed more cynical, almost, in a humorous way … just kind of a skewed perspective.”

Rogen had small roles in animated films (including “Shrek 3”), then campaigned for the “Monsters vs. Aliens” role as B.O.B., the enormous blue blob. Now he repeats that role in the NBC special, which has outer-space aliens slipping into Earth while people are trick-or-treating; it can be part of a Halloween week built around TV and candy.