Here is a clip from another UK TV show, this time from the early 80ies.
Marc is in his home studio, where he explains how he achieved human expressions on a realistic fawn.
Frank Thomas told me once that the animators couldn't have come up with he same results if it wasn't for Marc's thorough and extremely useful research.
Characters like the ones in Bambi could easily look overly sweet and kitschy, but when you have artists involved with Marc's caliber, that's not going to happen. Instead the film's cast is portrayed with unparalleled elegance and beauty.