Not all monsters who metamorphose do so via the same process. Common among monsters who increase in size between life stages is pucker metamorphosis. Puckers are a naturally-occurring phenomenon independent of the existence of monsters, and arose in the soil of The Farmlands long before pip-seeded life existed there. They are satellite extensions of Yaia herself, and share her genetics. A pucker is a subterranean pocket of magical gases surrounded by soft, fleshy tissue and connected to the soil’s surface by a sphincter. A monster seeking to undergo pucker metamorphosis enters the pucker through the sphincter. The pucker’s elastic walls expand to accomodate the monster, while the nutrient-rich lining and magical gases nourish the monster and facilitate its physical transformation between life stages. Once metamorphosis is complete, the monster vacates the pucker through the sphincter, leaving the pucker available for other monsters. Pucker distribution typically appears random, and puckers often grow alone, sometimes kilometers apart from each other. However, they can sometimes be found in "puckergrounds": large clusters of 10-50 puckers growing inches apart. What causes a puckerground to develop is unknown.