Tyrannosaura Wrecks is the monster that was imprisoned in the caboose of the Starlight Express in Dragon Quest IX, behind a door that seems to lead to another dimension. She's fought as an extra boss after completing a few extra quests.

Apparently, she's a goddess of destruction, so powerful that she can reduce entire continents to dust with a single finger. According to the Bestiary, she belongs to a very powerful group called the Hackson Five, and she killed three of her brothers and members of that group: Tyrannosaurus Wracks, Tyrannosaurus Wrocks and Tyrannosaurus Wrucks.