"You nearly mistake it for a boulder, and then you spot a crease in its hide as it draws a slow, hibernative breath. Suddenly you understand the saying among pig farmers: always fear large rocks."
Very dangerous foe to low level and unprepared characters that can randomly be found sleeping all around Qud.
It is relatively easy to avoid waking up, but sometimes other enemies or companions get the brilliant idea to go attack the slumberling even though it isn't being a threat. Oftentimes, the slumberling will choose to target the player regardless of who woke it up, so it is wise to pull back if another creature is moving to attack it.
It can easily maul weak characters in few rounds of combat and charge over long distances like chitinous puma can.
The slumberling will often fall back asleep even in the middle of combat or pursuit, making retreat a highly viable option for surviving an encounter.
Note that beguiling, or dominating a Slumberling while it is asleep will not wake it up. Therefore, if you want to use mental control on one make sure you wake it up first.