Yes, he dies when after he saves Harry, Hermione, Ron, and others from the death eaters. Pretty sad, =(
Yes he is.
Bellatrix kills him in Harry Potter and the Deathly Hallows
Dobby's age was never mentioned in the series.
Yes he was nice because he saves Harry in the Deathly Hallows
Dobby and Kreacher.
In "Harry Potter and the Deathly Hallows," Dobby the house-elf is killed by Bellatrix Lestrange. During the Battle of Malfoy Manor, Bellatrix throws a knife at Harry and his friends as they Disapparate, and Dobby is hit by the knife as he apparates them to safety. Dobby dies in Harry's arms shortly after, leading to a heartbreaking moment in the series.
Dobby died in Harry Potter and the Deathly Hallows.
Saves peoples' lifes then gets killed by Bellatrix Lestrange.
When Dobby dies. The chapter entitled: "The Forest Again"
"Dobby didn't mean to kill anyone. Dobby only meant to maim or seriously injure"
Several of his friends died; Fred Weasley, Dobby and Remus Lupin to name a few.
He has been in the second film: Harry Potter and the Chamber of Secrets and Harry Potter and the Deathly Hallows: Part 1.