Hazers have small bodies with colored splotches, a varied amount of tentacles (ranging from two to six), and a colored eye with a black pupil. When a Hazer dies, its skin darkens, its eyes turn gray, and its body deflates.
On land, Hazers wriggle and flop erratically. When in water, they propel themselves to swim or simply float on the surface. They can be fed to Lizards to tame them.
When thrown on land, stabbed, or bitten by a creature, they spray a large cloud of navy blue smoke, which temporarily blinds aggressive creatures and masks Slugcat from view. This can be used to pass aggressive creatures safely, and is especially useful for crossing Scavenger Tolls and passing under Dropwigs without detection. Smokescreens fade shortly after emission, killing the hazer and leaving it permanently deflated. Deflated hazers can be eaten for one food pip and living ones can be swallowed and regurgitated.
When not moving on land, Hazers blend into the background similar to White Lizards, leaving only an eye and their colored splotches visible. Hazers can still blend into the background when held by the player.
Hazers eyes and splotches vary in color. Hazer skin can be blue or green, which determines the color of other features. Blue Hazers have red, orange, or yellow eyes, with splotches ranging from gray to blue. Green Hazers can have pink or purple eyes with splotches that can be green, gray, or turquoise. The tips of Hazers' tentacles can also fade to the color of their splotches.
Hazers, despite being defenseless and slow moving on land, are almost never found in water in the base game, instead being placed on land next to bodies of water.
Five out of fourteen total Hazers spawn into the game world already dead, six out of fifteen for both Monk and Hunter.
Though they are creatures, they are placed in the rooms as objects. As such, they are swallowable (when alive), and respawn after 7 to 10 cycles (with variations up to 38). Among these variations, living hazers tend to take more time before respawning than dead ones.
When regurgitated, live hazers have a 40% chance to copy the player Slugcat's color.