Well of Transformation

The Well of Transformation is a well of special water on the planet of the Tlakakans that dissolves the body of whomever enters it, leaving only the spirit/soul, which then forms a new body of whatever sort their heart desires. The Tlalakans use it to change into merpeople so that they can secretly use the waterways for their rebellion. Any drone that enters the pool, being a soulless machine, is immediately dissolved to nothing as if by acid, but Transformers can use it safely. It seems to repel normal water, because its effects don't spread through the seaways.

From Teletraan I: The Transformers Wiki, a Wikia wiki.