titanic size: If the tarrasque is knocked prone, the resulting force of the crash generates a 10d6 force damage burst traveling 120feet outward from the tarrasque & slaughtering well meaning peasant millitia archersBut... but... imagine the devastation! The crash! (Also keep in mind that most ways of knocking a creature prone are limited to one or two size categories above your own... so you'd only be able to do it if you got to (whatever size is under Titanic) Colossal? Or at least huge. Which would be AWESOME.
