The Ewecus is an aggressive Mob that has a 50% chance to spawn at the end of a series of Suspicious Dirt Piles. It utilizes the same increased chance of spawning as a Varg does, starting off at 5% on Day 1 and gradually increasing to 33% by Day 100 (these values will be halved for finding the Ewecus specifically). This makes hunting for Koalefants increasingly riskier.
The Ewecus has a short-ranged melee attack and a long-ranged projectile. When it uses its short-ranged attack, it will attempt to kite the player. The projectile attack, in which it spits mucus at the player, will halt the player's movement on impact, similar to being frozen solid in Reign of Giants. The player will escape over time, but the player can escape faster with the help of befriended Pigs, which will free the stuck player immediately. In Don't Starve Together, this can also be done by other players.
- The Ewecus was introduced to Don't Starve Together in the Stuck in the Middle with Ewe update. It was later added to Don't Starve in the Quality of Life update.
- The Ewecus is considered to be part of A New Reign, even though it was introduced before the official start of the beta branch.
- The name "Ewecus" is a portmanteau of the words "Ewe" (a female sheep) and "Mucus".
- If the player manages to herd an Ewecus in a pen consisting of second tier Walls, the player can keep it as a pet without danger, since the Walls intercept its projectile attacks.
- Wickerbottom's description of the Ewecus (Ovis chalybs) is Latin for "steel sheep", a reference to the steel wool it drops upon death.
- From the game's files, there are few unused files for the Ewecus' body with most of its wool shaved off, originally meant to be shaved with a Razor for Steel Wool, similar to the Beefalo.