Time Magazine recently spoke to VFX Supervisor Erik Nordby to discuss the challenges faced when producing the first live-action Pokémon film.

“Animating animals, as in recent live-action remakes of titles like The Jungle Book, is one matter. But transforming adored fictional creatures that have been drawn in one specific way for two decades is another entirely. The process saw more than a thousand digital artists across the world working for three years through trial and error, all against a backdrop of ceaseless debate.

The team settled on around 65 Pokémon that would appear in the movie and began trying to solve their anatomical riddles. “We’d build them as if they were an actual animal,” Nordby says of his team at the Moving Picture Company, a visual effects company. They created detailed skeletal and muscle systems for each Pokémon, visited zoos and consulted animal experts in order to have a reference point for every beak, tail or paw. The waddling four-legged Bulbasaur, for example, was based on a baby bulldog in its playfulness and top-heaviness. Pikachu started off very rabbit-like, but eventually became a cumulative creature inspired by the movements of marsupials and marmosets and the moonlike eyes of sugar gliders.”

Read the full interview here.