Jellyfish Sprite
Red sprites or the tentacle-like spurts of red lightning in the sky during a storm are sometimes referred to as Jellyfish Sprite (because of their shape). There are also some that are vertical columns of red light and those are called carrot sprites.
They are ultra fast electricity traveling through the atmosphere towards space and are extremely rare (they last a tenth of a second). They can also be seen from space.
The picture above was captured on Mt. Locke in Texas (July 2nd, 2020) by Stephen Hummel.