You can change your appearance into anything without using an action (usually a surface, building, island, or patch of air) that is no larger than 500 miles in every direction. Your statistics, other than your size and state of matter, are unchanged in this state.

You are immune to all damage and conditions and do not have to breathe. You can negate any magical effect if you wish to do so.

Whenever a creature or object smaller than 500 miles in any direction touches you, you may engulf it. While engulfed, it can do nothing. It takes any number of acid damage (your choice) at any time you wish. You may obliterate it at any time. 

You may teleport anywhere at will, no action required. You can also cast plane shift at will.

You can see anything anywhere.

All of your ability scores are 500.