Short answers, pulled from the story.
The BAFTA Award for Best Animated Film was first introduced at the 1955 ceremony. The original category covered both short and feature-length animated films until it was last awarded at the 1982 ceremony.
The award was re-introduced at the 2007 ceremony, now as a prize exclusively for feature-length animated films. Happy Feet, directed by George Miller, Warren Coleman, and Judy Morris, was the first winner under the re-inaugurated category.
Pixar has won the most, with 8 wins from 19 nominations since the award's re-inauguration in 2007. Winning films include WALL-E, Up, Toy Story 3, Inside Out, Coco, Soul, and others.
No. DreamWorks Animation has received five nominations - for Flushed Away, Shrek the Third, How to Train Your Dragon, Puss in Boots: The Last Wish, and The Wild Robot - without any of them winning.
Wolfwalkers, a co-production between the United Kingdom, Ireland, Luxembourg, and France directed by Tomm Moore and Ross Stewart, won the award. Klaus and Guillermo del Toro's Pinocchio, both from Netflix, also won, and both had non-US production involvement.
DreamWorks Animation holds the record with five nominations and no wins. Aardman Animations has also been nominated six times, winning once, giving them the most nominations of any British studio.