These can be found in the Smokey Well west of Pollnivneach, which can be accessed via Flying Carpet.
They are very weak, and can be hit quite high on with range. There are plenty of them, and plenty of range spots, but they can be quite spread out. A slayer helmet is DEFINITELY needed here. They are very good slayer and ranged xp.
Usually just drop a few coins, and have an extremely small chance of dropping Dragon Chainbody. They also drop quite a lot of rune arrows, as well as crimson charms.
dust devils dusties