Crabify

Targeted creature rolls a wisdom check (add 2 to their roll if they're proficient in wisdom). If the wisdom roll is failed and there is no crab nearby then they believe that they are that of a crab, if there is a crab in the proximity of 50 feet then the crab, and the victim's minds are swapped for the main duration +2 rounds.

When the crab is destroyed their mind is returned to their body

The crab's personality may be chosen by the DM and could result in being more dangerous than the initial foe, while the crab is in control swap the Wisdom and Intelligence of the crab to the victim.

The duration of the spell can be that of 2 rounds or a 1d4 roll