Bubble Cage

You conjure a large bubble that can trap creatures and objects within 30 feet. The bubble is a 10-foot radius sphere that can trap a large or smaller creature. You may move the bubble up to 30 feet in any direction as a bonus action on your turn. If the bubble is summoned on top of a creature or enters a creature's space, that creature must make a dexterity saving throw or become trapped in the bubble.

A creature trapped in the bubble is restrained. The bubble has an AC of 10 and 40 hit points, and has resistance to all damage types except piercing. When your concentration ends, the bubble pops and releases the creature. The bubble may capture one creature at a time.