I was inspired by the corpse flowers of two different species, the Rafflesia and the Amorphallus Titanum. The limbs are made of twisted trunks of the Bristlecone Pine, a tree that can live up to 5,000 years.
The colossus uses its limbs to support its weight as well as defensive/offensive purposes.
The Corpse Flowers may develop teeth so that adventurers lured by the strange blossoms become an unwitting prey. The vegetation on the colossus will continue to grow at a cancerous rate making it the embodiment of the virility of the life element.