User blog comment:Mckrongs/Rust Duramboros Discussion/@comment-4555457-20111105010414/@comment-74.240.186.26-20111201225640

it's possible that it charges similar to the barroth than while doing it can also be making a mud or dirt ball and when it ends the charge it pushs the ball towards the hunter or ends it by cutting the ball in half making to smaller ones. Another possiblity is a barroth showed up in the area and covered the hunter with mud right when he threw a dung bomb.