Your Head A Splode is simliar in function as All Your Base Are Belong to Us.
It originated in a Strong Bad video game, where upon your death a computerized Strong Bad voice would say, "Your Head A Splode."
Cats: All your base are belong to us!
Strong Bad: Your head a splode!
Cats: OOOOooo.
A word used to describe when a character in a story (typically best friend to the protagonist) dies suddenly during a climactic moment.
Man, Jackie Welles really rex-sploded huh?