The model is a paid model found on Thingiverse. I'm not sure who the original creator of this model is. There are quite a few of the same thing under different users.

Here is the link to the model: https://www.thingiverse.com/thing:3302444

Model Description:
The massive burrowing monster known as the purple worm terrorizes the creatures of the Underdark as it chews through solid rock in pursuit of prey. A dim-witted, ravenous force of nature, this creature regards anything it encounters as food. (source = D&D Beyond)

Printer and resin used:
Elegoo Mars Pro 2
I dont remember the resin I used.

Slicer:
Lychee Slicer

Paints:
Unless otherwise stated, all the paints are from the Army Painter D&D line of paints.

Steps and Planning:

1. This was printed when I still used my Elegoo Mars Pro 2. I merged all the parts together to get a single print to not have to glue anything together. The model had some of the spikes on the left side fail and turn out flat. 
2. I didn't think I would be interested in painting this one in too much detail. I went into it thinking I would just spray some Purple Worm paint from the airbrush and that was going to be it. But after painting the purple on top of the black primer I saw some potential, so I sprayed some dark washes to form the under shadows, and then a white with a bit of purple for the zenithal top. 
3. From there I saw even more nice things I could try and decided to spend a few hours working on this one. 
4. Painted the teeth and body spikes black, added some acid colour to the very deepest parts inside the mouth.
5. I sprayed some more washes, a mix of red and blue to add more shadows to the top and other crevices.
6. Oak Brown was used for the base followed by light brown. Then I dry-brushed some dungeon stone gray all over the rocks to make it blend better.
7. The base was completed using the things in the Army Painter Battlefields Basing Set.
8. I though the teeth were kind of boring in just black, so I dry brushed some blue on them, followed by black dry brush and some blood red spots to the teeth.
9. I did a final spray of matte varnish and called it good enough for me.