These things each hydroid jelly lacks:
brain, eyes, and heart. Sans bony backs,
like weird pelagic blister packs,
they drift in colonies called smacks.
Woe to the toe a jelly thwacks!
Though host to scads and yellow jacks
their tentacles, in search of snacks,
bear stingers sharp as carpet tacks.
Think: Lethal-Weapon-Water-Sacs.