These are not bosses but super tough and they are like landsharks.
They live in the SW island, you will need a Springboard to jump the bridge at A3 and get there.
You cannot tank these things, shoot and run!
If you stand on a paved tile, they wont attack you, use this to step into the sand, quickly back away into pavement and shoot at them while they jump but beware the scorpions, you can cheese them using clever use of torches.
You need the pirate captain's pickaxe to get the husks. (It costs 5 platina)
Mummies also sometimes drop them, which sell for a lot of gold.
This is the strategy I use to farm sandworm husks, I use the steam rifle that the steamlord drops.
![](https://s2.save4k.ru/pic/slvC9SpMAyA/maxresdefault.jpg)