Wasp 121b

Wasp 121b also known as Tylos is the first exoplanet found to contain water in an "extrasolar planetary stratosphere" (an atmospheric layer in which temperatures increase as the altitude increases)

This exoplanet is apart of the constellation named "puppis" and around 858 light years away from us . Its mass is 1.157 Jupiters, it takes 1.3 days to complete one orbit of its star. The star it orbits is also called Wasp-121 which is super duper confusing. 

The day side of the planet reaches up to 3000 degrees celcius. This causes heavy metals to be lofted into the atmosphere of the planet, Which makes it a gas giant