Occasionally visible as a pillar of gas on the horizon, gradually dispersing.
They are blobs of gas, contained in translucent skins, bobbing just above the ground. They range from child-size (common) to full-grown-adult size (much rarer). Some lunatics claim to have seen bloats as large as a house on distant desert plateaus.
They appear to have no organs or nervous system – unless there is something microscopic to the point of invisibility in their skin – but they seem to possess some sort of intelligence or at least curiosity. Sometimes a pack of them will come upon a caravan, bobbing gently above the ground, and encircle the animals and caravaneers, harmlessly nudging at them.
Experienced travelers know not to molest the bloats. Sometimes a nervous hireling will slash one open. The skin parts easily at the faintest blow, and immediately the caustic gas within disperses, dissolving flesh as it expands.
Rumour has it that certain unscrupulous desert-raiders collect bloats in secret and are trying to work out how to launch them at enemies.
(A BLOAT has 1 HD and no defences to speak of. If broken, it fills an area about 16x its size with gas, which deals 1d6 hp of damage per round to any flesh within the cloud. The gas disperses within about a minute.)