A genre-bending tale of a boy trying to fulfill his unrequited love for a girl who has risen from the dead. It tells the story of twin brothers Patrick and Carol Darling, newly graduated from high school and struggling to come to terms with the mysterious disappearance of their friend, the bright and beautiful Wendy Hearst. When a drive through the countryside surrounding their suburban community leads to the discovery of Wendy's mysteriously animated corpse, the boys secretly transport the un-dead Wendy to an empty house in hopes of somehow bringing her back to life. As the sweltering summer pushes on, they must maintain the appearance of normalcy for their friends and family as they search for ways to revive the Wendy they once knew, or, failing that, to satisfy their own quests for love amongst the living and the dead.
Rody's dogs are killed offscreen and what's left of their bodies is shown. The dog shown in the beginning of the movie is implied to be killed, but nothing is shown.
Live dogs are fed to Wendy offscreen. A live rat is picked up by the tail and later fed to Wendy. Some goldfish are kept in a bowl that is too small for them.
Patrick and Carol try to feed Wendy raw meat and a live rat, she mostly vomits up what they feed her and she gets covered in blood / gore. A dead, partially rotting possum in a trashcan is shown with some gore.
Up to viewer interpretation. While it's not explicitly stated if Wendy is LGBT, there is some implication that she might've been before she died / turned undead.
Carol tells Addy "[Wendy] said she'd marry you if she could turn into a boy". They don't make any further comments about her sexuality, but that is common for closeted people to say.