The vegecrawler split from its ancestor, the vegehopper in Russ River, and spread to Yokto Rocky. It has evolved dark patches of photosynthetic cellulose on parts of its skin. These dark patches, though better at photosynthesizing than its normal skin, are heavier. Because of it, jumping is very hard for the vegecrawler. It now uses its tentacles to move in a crawling fashion, while using its flippers as a moving aid.
In the dry and freezing Yokto Rocky, the vegehopper was unable to moist its skin well enough to survive. Its descendant, the vegecrawler, adapted to this by expanding the use of its gill chamber to hold much more water, transporting it, through intricate webs of veins, to its entire body. This new adaptation enables it to move across the Rocky, eating and sunbathing during the warm months of the year.
In these warm months, the vegecrawler will gather as much food as it can, eating anything it can get its hardened mouth to chew on, and even the shards of the stinging glassball's protective coating. When the colder months come, it will return to the river to mate and eat under the frozen water, making small holes in the ice, where it can, so it will be able to go and photosynthesize when the short days' sun rise.