Steel Maw

You learn how to turn your body into a living prison. You gain the following benefits:

• Your strength score is increased by 1.
• You can use your action to try to capture a creature grappled by you within your armor. To do so, make another grapple check. If you succeed, the creature is restrained, incapacitated and in total cover.
  
  At the start of it’s turn, a creature inside of your armor can only use it’s action to contest against your grapple check but is otherwise incapacitated. Additionally, a creature that can teleport without the use of somatic components may do so.
  
  While a creature is captured within your armor, you no longer move at half your original speed, instead,  when you move, your speed is reduced by 5. When you take an action you must do a Strength (Athletics) check at DC 8 + the captured creature’s Strength Modifier or lose your action.