He said the problem turned out to be a tiny metal gun he had taken from a keychain and given to his "Toy Story" Woody doll, which did not come with a gun in his belt holster.
Hazen said he posted a picture on Reddit of the disarmed Woody at airport security with the caption, "security just confiscated his 'weapon, "keep the world safe boys..."
He said he was surprised when he landed in California to see how many comments the post had.
Hazen said he takes the Woody doll with him when he travels to take pictures for his son, Dylan, 7, who loves the "Toy Story" films.
"I brought him through Heathrow and never had a problem. I've taken him to New Zealand, Montreal, Barcelona, at least 30 cities," Hazen said.
Heathrow Airport declined to comment on the specifics of the situation and said security rules are dictated by the Department for Transport.
