In the movie, The Hobbit: The Unexpected Journey, Smaug has 4 legs. If you look closely in this scene where he crawls into the mountain, he has 2 fore legs and 2 back legs.

In the next movie, The Hobbit: The Desolation of Smaug, he has only back legs.

Why were the fore legs removed?

Was it due to an oversight? An error in CGI?

Or was it because the book said he had only 2 legs?

In the movie, The Hobbit: The Unexpected Journey, Smaug has 4 legs. If you look closely in this scene where he crawls into the mountain, he has 2 fore legs and 2 back legs.

In the next movie, The Hobbit: The Desolation of Smaug, he has only back legs.

Why were the fore legs removed?

Was it due to an oversight? An error in CGI?Or was it because the book said he had only 2 legs?