Wow, this is a big model! Another fantastic "miniature" from the D&D Nolzur's Marvelous Miniatures line by WizKids. They're just killing it with this amazing sculpt right from the pages of the 5e Monster Manual - it's nice to have licensed models.
This was a fun paint. Basically every paint dropper which had the word green in it was used on this model - yellow-green, blue-green, brown-green, and green-green. I would pick an origin point and would follow the vine along until the end point. I figured that would give me a more interesting and dynamic figure than just a generic medium green. A light brown to represent some sort of wood protrusions for teeth and then a dark red with medium red highlights for the leaves and the mushroom give it a bit of pop. Added some white dots on the mushroom tops for that classic fantasy mushroom look.
I called it the "SHAMBLER" as trying to put on shambling mound was too many characters for the base.
As noted previously, WizKids should publish the sculptor.