For the event, see The Brood Mother.
Broodmothers are a type of spider enemy in Diablo Immortal. They are encountered in Wortham, Ashwold Cemetery, Dark Wood, Shassar Sea and Mount Zavain.
In-game
Broodmother primarily attack by spitting poison. When in melee, they deliver a powerful slam with poison claws that stuns prey. They can also lay eggs which hatch into Volatile Spiders.