The War with Grandpa tell story about "Peter is thrilled that his Grandpa is coming to live with his family. That is, until Grandpa moves into Peter's room, forcing him upstairs into the creepy attic. And though he loves his Grandpa, he wants his room back - so he has no choice but to declare war..".
Cast : Robert De Niro, Uma Thurman, Christopher Walken, Jane Seymour, Oakes Fegley, Laura Marano, Rob Riggle, Cheech Marin, T.J. McGibbon, Isaac Kragten, Juliocesar Chavez, Lydia Styslinger, Drew Scheid, Faizon Love, Colin Ford, Poppy Gagnon, Gage Lawson, Heather Johansen
- Runtime : 94 minutes (1' 34")
- Genre : Comedy Family Drama
- Production : Marro Films EFO Films Tri G West Madison Entertainment
- Release : August 27, 2020
- Countries : United States of America
- Languages : English