Dirt eater

Dirt eaters are concept undead creatures seen only in one piece of concept art by Blizzard artist Travis Thammer. They may have been a canceled unit type for Warcraft III. Based on the caption, dirt eaters are half buried in dirt when moving around. They seem to attack by throwing rocks.

Trivia

 * "Dirteater" is also a possible name combination for the permanent ghoul pets summoned by death knight via Master of Ghouls.