Alice in Wonderland was first filmed in 1903. Only one, partial print of this early version is known to survive, and this has recently been restored by the British Film Institute.
There are around eight minutes left now of the original twelve-minute film. One of the missing scenes featured Alice’s encounter with a giant puppy (or rather, an average-sized puppy: it’s Alice who’s shrunk at this point). The dog was played by Blair, who was a pet of one of the directors, Cecil Hepworth. All that’s left of this scene are a couple of frames, including the one above. (You can see more of Blair in Hepworth’s 1905 film Rescued by Rover.)
As for the restored Alice in Wonderland, you can watch it below, or at the BFI site, which also has notes on the history and restoration of the film.