*iPhones
They seem to have the highest computing power to battery size ratio among mobile devices in general.
One one hand it's great because they're powerful, on the other this here happens.
Around Christmas there was this sand game which was really neat, but sucked my SO's battery dry in moments going a stable 40fps.
My Galaxy S8 ran it slower and choppier, but considerably longer.
I don’t know what else it is, but it is a great DDoS tool for batteries.