First appearing in “The Mandalorian”, the rattan is a giant horned animal native to the desert planet Arvala-7 and has a woolly coat that is usually covered with dirt – hence the name. theirs (via Wookiepedia). Their horns are very large. As thick as a tree trunk and almost as tall as Din Djarin himself, a single stab equals certain death. When not roaming the desert, they seek shelter in caves and lay eggs that share the same exotic plumage.
In Season 1, Episode 2, “The Child”, Din Djarin is forced to fight a man when a group of Jawas ask him for one of these eggs, which they consider a delicacy. Djarin performs a thorough and seemingly dying defeat when Grogu uses the Force to lift the monster into the air, rendering it harmless. Djarin kills it after it falls and then takes a cactus skull as the mark of his clan.
Mud is certainly a formidable foe, although it seems unfortunate that Djarin has had to fight it in the first place. The pitiful thing was simply to do its own thing in that cave, watch over its eggs, and Djarin ran in and killed it just to pay some Jawas. Perhaps in the future, Djarin will think twice before attacking one.
https://www.looper.com/735163/the-mudhorn-in-star-wars-explained/ Explaining Mudhorn in Star Wars