Porpita porpita

The blue button looks like a small, bright blue jellyfish fringed with tentacles, but it is a colony of many small hydroid animals rather than a true jelly. It drifts at the surface and now and then washes up in numbers, as it did on Texas beaches such as Galveston Island in the summer of 2023. It is worth recognizing because a blue drifter on the sand could also be a Portuguese man o' war, which stings far worse. The blue button's white-tipped tentacles carry stinging cells, but it is not deadly to humans; the usual result of handling one is skin irritation. Look, and leave it on the sand.