Drown on Dry Land

''Drawing the shape of a sea creature in the sand, then pointing at your target transforms its lungs to gills. It gasps for air, but it can breathe only in water.''

The subject gains the ability to breathe water, but loses the ability to breathe in air. This spell can be used to make a creature “drown on dry land,” i.e. suffocate unless it finds sufficient water to breathe in.