Bearger's crawling animation is missing

In single player, Bearger used to have a crawling animation. Now it's not present neither in single player nor in multiplayer to my knowledge. He would typically walk on all fours while following player or looking for food, although I am not entirely sure when exactly he would crawl and when he would walk on two feet instead. Even if the crawling animation was removed on purpose, it would be great to see him walk on all fours again in certain circumstances. Here's an old video from single player game to illustrate what I mean by "crawling animation":