floater

An object or substance that remains on the surface of a liquid.

"There was a strange floater in the pond."

A person who works temporarily in various departments or locations.

"She works as a floater, covering different shifts."

Small specks or strands that appear to drift across one's field of vision.

"He sometimes sees floaters after staring at bright lights."

An un-flushed piece of faeces floating in a toilet bowl.

"Someone left a floater in the loo."