Bigby and the Beanstalk

You cause a thick, sturdy beanstalk to sprout from the ground at a point within range. The diameter of the beanstalk at its base is 10 feet and it grows upwards to a height of 120 feet over the course of 2 rounds. The growing stalk anchors itself to sturdy objects such as walls or ceilings, and grows through objects that do not fully obstruct its space (such as tree branches), but is stopped by solid objects or structures.

Any creature standing on top of the beanstalk when it is created (or any creature that moves into its space while it is growing) must succeed on a Dexterity saving throw or be lifted by the beanstalk, provided the beanstalk can support their weight. A creature can choose to fail the save. If the beanstalk is prevented from reaching its full height because of a ceiling or other obstacle, any creature on top of it takes 4d6 bludgeoning damage and is restrained, pinched between the beanstalk and the obstacle. A restrained creature can use an action to make a Strength or Dexterity check (the creature’s choice) against the spell’s save DC. On a success, the creature is no longer restrained and must either move off the beanstalk or fall off it.

The beanstalk features numerous strong leaves as well as hand and footholds, making it easy to climb. A creature falling through the beanstalk takes half as much damage from the fall, as the beanstalk's leaves cushion its descent. The beanstalk can support up to 15,000 pounds of weight, or double that amount if anchored on its upper end. The beanstalk can easily support huge creatures or objects that do not exceed its maximum weight limit, but may struggle with larger things. It may even support small structures, depending on their weight. The beanstalk is able to support its own weight without issue.

If the beanstalk anchors itself to a sturdy mobile object (such as an airship or siege engine), the object is restrained until it (or a creature attempting to free it) succeeds on a DC 34 Strength (Athletics) check. The beanstalk has an AC of 5, 150 hit points and it can be cut through or destroyed.

If more weight is placed on it than the beanstalk can support, or after the spell ends, the beanstalk begins to wither and it takes 50 damage each round. Re-casting this spell or casting plant growth on an existing beanstalk heals it for 20 hit points if it is damaged, or refreshes the duration of the spell if it is not damaged. When the beanstalk is destroyed or fully withers, it crumbles to dust and vanishes.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the maximum weight limit, height, or duration (choose one) of the beanstalk is doubled for each slot level above 6th. For example, if you cast this spell using a 9th level spell slot, you could change the duration to 16 hours and the height to 480 feet.