Place it at the peak of a boss reveal, after a short warning cue and before the fight begins. Start with Metal Gear Alert to signal danger, then let this roar mark the entrance, and finish with Mortal Kombat Fatality once the boss is beaten.
Über diesen Sound
This is the deep, guttural roar of Vakishim, the monster from Ultraman Mebius, lasting just under three seconds. It sounds huge and threatening, like something enormous has just woken up and is ready to attack. The roar itself was taken from the 1957 film The Land Unknown, and it later became widely recognised as Bowser's roar in Super Mario 64.