Friendly to a point, he can seem quite erratic at times, but over all he is incredibly lazy and easily made bored. He doesn't mind upsetting people to start a little fun and chaos and finds it annoying if he has to make much of an effort for things.
He loves apples and can sometimes bend to a persons will in order to get one.
Despite being comical and generally...nice? Ryuk ultimately doesn't care about anybody but himself.
Ryuk has been taken from the end of the series [Manga]
Ryuk looks very much like his usual self while human. He has a long face with large eyes, one of which is lazy. His hair is black and messy, sticking out at the ends. His lips are big and wide while his nose is small.
Not as tall as he ought to be, he still towers above most patients. His shoulders are wide, arms are long as are his legs. And his wasit and limbs are all rather skinny.
His skin is pale.
Ryuk has his Shinigami eyes and can therefore see a patients name and lifespan. Generally this won't affect him since he's not that interested.
He's mainly not interested because he has his Death Note here....but it doesn't work.
He can understand all earth languages and will hear English when faced with characters from strange universes and the likes.
While not invincible, injuries don't affect him quite as badly as it does others and can tend to heal faster. But they're still a pain in the ass and can be lethal.