Tar Pit

You magically summon a pit of bubbling tar, which appears on the ground in a 20-foot square centered on a point you can see within range. For the duration, a creature must spend 3 feet of movement for every 1 foot moved through the area. Furthermore, while a creature is in the area, it has a -2 penalty to its AC and Dexterity saving throws, and it cannot use its fly speed to move.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, area of the spell and the penalty to AC and Dexterity saving throws increase by 5 feet and 1, respectively, for each slot level above 3rd.