General Grawl is the main antagonist of the 2009 movie Planet 51. He is a high-ranking alien military officer who believes that his planet is under attack from alien invaders (in reality the "invader" is a clueless human astronaut who is no danger to anyone).
Driven by a fear of the unknown General Grawl becomes a menace to himself and his men as well as (somewhat ironically) his world as he becomes obsessed with not only capturing the "alien" but in either killing him or having his brain removed.
However in the end of the film, General Grawl is redeemed when he is rescued from his self-destructing base, making him finally realise that the "alien" was not a threat and also opening his eyes to the fact that blind ignorance and fear is far more dangerous than imaginary threats.
He is voiced by Gary Oldman.