I can't find anything in the PHB about how teleporting affects prone creatures. Teleporting automatically ends the restrained condition, I wonder if it also can end the prone condition.
Can a prone creature stand up during the teleport?
But there is a way to do it using magic items and the destination point.
Have a magic item like Safewing Amulet - lets you land on your feet when falling. Then Teleport to 10 feet above ground.
Tada! Standing from a teleport.
Using any combination like this works nicely.
Yes, if the creature is trained in Acrobatics.
It's because of this Acrobatics ability:
REDUCE FALLING DAMAGE (Trained only)
If a creature that has training in Acrobatics falls, it can make an Acrobatics check to reduce the amount of falling damage it takes. The creature can make this check whether or not the fall is intentional.
- Action: Free action. The check is a response to falling.
- Result: The amount of falling damage that the creature takes is reduced by one-half the check result (rounded down). If the falling damage is reduced to 0, the creature lands standing.
Example: The floor beneath Keira swings open to reveal a pit 40 feet deep. As a rogue, Keira has training in Acrobatics, so she makes an Acrobatics check to reduce the falling damage. When she hits the ground, she takes 24 damage (from a roll of 4d10). Her Acrobatics check result is 21, which is divided in half and rounded down for a result of 10. Keira’s check reduces the damage by 10, so she instead takes 14 damage from the fall.
Please note that one can attempt to reduce falling damage in response to any kind of falling at all. Actually being at risk of taking any falling damage isn't a part of the condition in the Action line.
Falling damage works like this (from the Falling entry):
Falling Damage: A creature takes 1d10 damage for each 10 feet it falls, to a maximum of 50d10. The creature falls prone when it lands, unless it somehow takes no damage from the fall.
Fast Alternative: If a creature falls more than 50 feet, it takes 25 damage per 50 feet, plus 1d10 damage for each 10 extra feet.
Importantly, when you fall for less than ten feet, you receive no falling damage. You might see how these two are going to come together.
An acrobatics-trained creature can teleport to the square (cube?) just above the one at ground level. This cube spans 5 to 10 feet above ground level, so the creature is at no risk of taking any actual falling damage (if they were to fall a full 10 feet, they'd be in the cube above). The creature falls, attempts to reduce their fall damage, and reduces their 0 falling damage to 0 on any roll at all (since skills don't have auto-failures on a 1). The creature lands standing.