Emblimpen

You cause a successfully targeted creature to rapidly gain weight. Effected creatures clothes and armor expand to accommodate their new size.

An affected target's speed is halved due to their increased size, it takes a −2 penalty to AC, disadvantage on Dexterity skill checks and Dexterity saving throws, and it can't use reactions. On its turn, it can use either an action or a bonus action, not both. Regardless of the creature's abilities or magic items, it can't make more than one melee or ranged attack during its turn.

If the creature attempts to cast a spell with a casting time of 1 action or more, they must make a raw DC 10 save. On a failed save, the spell doesn't take effect until the creature's next turn, and the creature must use its action on that turn to complete the spell. If it can't, the spell is wasted.

On a critical roll, double the duration of the spell.