Lost Soul

Lost Souls are undead enemies in Diablo Immortal.

There are two monsters named "Lost Soul." The first type is summoned by Manoruk, and sent towards the player in line formation. The second is located in the Domain of Horror, where their fully body appears, and they lob projectiles at the character.

Trivia

 * Lost souls appear as enemies in the Doom franchise, similarly appearing as floating skulls.