D&D 5E Sprite familiar firing sleep-needles every round?

[transtemporal]

Basically, he's spending a bonus action for a crappy chance to remove an opponent from the battlefield. Which is probably a good choice if the monsters take 3 or more rounds to take out or if the party is out of resources, but not if the monsters are super squishy.

 

[FormerlyHemlock]

Weirdly, only elves seem to have sleep immunity in 5e (and only to magical sleep). Even golems aren't actually immune to sleep, though they have magic resistance and immunity to a whole host of other stuff. Including poison, and like I said I'd rule that a creature immune to poison is also immune to the sleep effects of a poison that puts creatures to sleep.

Elementals are immune to the "unconscious" condition, and therefore immune to sleep spells.