A very scary electrostatic discharge is called Lightening.
EXPLANATION:
Electrostatic discharge is the discharge of the electric current between the bodies with different electric charge and various number of electrons.
During the thunder bolts lightening there occurs the electrostatic discharge because it equalizes the two electrically charged atmospheres temporarily.
The lightening is an electric spark produced in the atmosphere which is quite frightening and scary.
During lightening there is the exchange of billions of joules of energy.