This is somewhat of a rarity these days, but the effects team on Resident Evil created two fully-movable puppets to film the scenes involving the licker throughout the second half of the movie, including the insane climax on the train.
In the behind the scenes documentary that accompanies the Resident Evil home release, special effects and make-up supervisor Pauline Fowler revealed that one of the puppets was made of reinforced steel and could be used as a battering ram, so to speak, while the second unit was created in a way that it would correspond to every movement from the puppeteer.
There was some CGI for a few shots, but the team spent a great deal of time and energy perfecting the look and movements of the mechanical creatures so that they could be used as much as possible.