Grimlore's Grimoire
4-level Conjuration
An oleaginous wax covers the ground, walls and ceiling in a 30-foot radius sphere centered on a point within range and turns it into difficult terrain for the duration. The wax spreads around corners, covering all surfaces within range. When the wax appears, each creature standing in its area must succeed on a Dexterity saving throw or fall prone. A creature that enters the area or ends its turn there must also succeed on a Dexterity saving throw or fall prone.