The Archive of Esoteric Secrets

Stalagmite

2-level Conjuration

You conjure a piercing stalagmite below a creature that you can see within range, the target must succeed on a Dexterity saving throw or take 3d8 piercing damage and be knocked prone. If the target is already prone when the spell hits and they fail the saving throw, they take an additional 3d8 piercing damage. The target takes half damage on a successful save and is not knocked prone. The stalagmite itself takes up a 5-foot cube. You cannot cast this spell if the target creature is not less than 5 feet above solid ground.
 
At higher levels: This spell deals an extra 1d8 damage for every level you cast this ability at above 3rd.