Humans are to zebras as giant floating brain-jellyfish are to humans

Ooh! Ooh! Okay. Creature idea!
A giant floating brain-jellyfish that can move very slowly but across any terrain. In the past, they crafted darts which they threw with great distance and accuracy, but in the past 10,000 years they have increasingly cooperated with others of their kind to build elaborate traps/farms for humans. One example: cities.