A whiny child.
Emily is very whiny; she keeps complaining about trivial things.
The child is not tired, hungry, or uncomfortable, but starts a whiny, fussy cry.
whiny stuff about no-one understanding you.
The main character is a little too whiny for the reader to care.
If you are sick of spending the holidays at grandma's house with nosy Aunt Sue and her whiny kids, then consider cruising the Nile this Christmas.
They're kind of filed away in my brain alongside Placebo, whiny miserabilist indie tripe with vaguely Goth leanings.