Leo chuckles at the suggestion he spent time on the set working with actual pairs of lions, tigers and giraffes.
"Doves," Leo says. "I was just supposed to chase the doves and they fly away."
Most other animals were computer-generated, he says.
Friends and other kids are "unfazed" by the Carroll boys' fame, Vicki McHugh says. That doesn't keep inquiring minds from asking Leo about Russell Crowe.
The iconic actor with the reputation for being temperamental was nothing short of "amazing" to fellow actors on the set, Leo says. Especially with the kids, even if it meant putting his money where his foul mouth was.
"All of the kids on the set said that, because he was swearing so much, he had to put money in a jar," Leo says.
Crowe, the teen noted, was happy to oblige "as long as it went to charity," dropping a $50 or $100 bill in the jar in the morning and saying, "'That should take care of me for the rest of the day.'"
"Russell was great, great to Leo, friendly and nice during the entire filming," McHugh says. "He was always thinking of little entertaining things to do for the kids. ... He couldn't have been any nicer.
"And Emma Watson," she adds, "oh my gosh!"
The Harry Potter book series was Leo's favorite. When he met Emma Watson, who played Hermione in the Harry Potter movies and is cast as Ila in "Noah," Leo acknowledges being awe struck.
"It was really amazing because I had never thought I would meet a person like that," he says.
"Mostly," he adds, "we would talk about this movie, or I would be asking her, like, how they did things in "Harry Potter." And she's just a totally, friendly, nice person."