Baleful Transformation

This spell begins transforming a creature that you can see within range into a new form. An unwilling creature must make a Wisdom saving throw to avoid the effect. The spell has no effect on a shapechanger or a creature with 0 hit points. The target continues making Wisdom saving throws at the end of each of its turns for the duration of the spell or until it accumulates three successes or three failures (the success or failures do not have to be cumulative). After three successes the spell ends. After three failures, the target is polymorphed into a new form for the remainder of the spell’s duration.

You choose one of the following penalties to apply to the target when you cast the spell:

Frog’s Weakness: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Strength and its carrying capacity is reduced to 15 pounds. After three failed saving throws, this penalty ends and the target is transformed into a frog. This transformation lasts until the spell ends.

Gas Spore’s Frailty: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Constitution and it has disadvantage on rolls to maintain concentration. After three failed saving throws, this penalty ends and the target is transformed into a gas spore with a size of Small instead of Large. This transformation lasts until the spell ends.

Scorpion’s Stupidity: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Intelligence and it is not capable of understanding any languages (but can still speak). After three failed saving throws, this penalty ends and the target is transformed into a scorpion. This transformation lasts until the spell ends.

Stick’s Speechlessness: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Charisma and it is not capable of speaking any languages (but can still recite verbal components for spells and understand languages). After three failed saving throws, this penalty ends and the target is transformed into a twig blight. This transformation lasts until the spell ends.

Tree’s Rigidity: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Dexterity and it can have no move speed higher than 20 feet. After three failed saving throws, this penalty ends and the target is transformed into an awakened tree with a size of Small instead of Huge. This transformation lasts until the spell ends.

Xvart’s Obliviousness: The target suffers a 1d4 penalty to any ability checks or attack rolls it makes using Wisdom and any special senses it has are reduced to a range of 30 feet if not already shorter. After three failed saving throws, this penalty ends and the target is transformed into a Xvart. This transformation lasts until the spell ends. If you do not have Volo’s Guide to Everything, you can use the statistics of a goblin to represent a xvart.

When the target full transforms, its game statistics, including mental ability scores, are replaced by the statistics of the chosen beast. It retains its alignment, personality, and current and maximum hit points.

The creature is limited in the actions it can perform by the nature of its new form, and it can't speak, cast spells, or take any other action that requires hands or speech.

The target's gear melds into the new form. The creature can't activate, use, wield, or otherwise benefit from any of its equipment.

At Higher Levels. If you cast this spell using a spell slot of 6th level, the duration is concentration, up to 10 minutes. If you use a spell slot of 7th level, the duration is 8 hours. If you use a spell slot of 8th level, the duration is 24 hours. If you use a 9th level spell slot, the spell lasts until it is dispelled. Using a spell slot of 7th level or higher grants a duration that doesn't require concentration.