A named used for canned energy drinks containing lots of sugar and taurine such as Monster, Rockstar and red bull that people associate with heart attacks.
Mason: You look tired, James
James: Yeah, I could do with some Heart-attack juice
The concoction of whiskey and crab blood. When a pony is feeling weary, one should feed them this mixture to instantly increase the pony's overall stamina and abilities. War juice can also be consumed by the bravest of humans for similar affects.
Alex: Did you see Bryan last night?
Chris: No, what happened?
Alex: He drank warjuice all night and ended up ripping his shirt off and boxing police officers!
Chris: No way! What happened to him?
Alex: No idea, he just kept running...