From publisher blurb:
Mythic Monsters: Colossal brings you a dozen and one terrifying titans to shake, rattle, and roll your heroes into submission. From CR 10 to the first CR 30 creatures to appear in the Mythic Monsters series, you'll find challenges fit to shake the foundations of heaven and grind the weak underfoot in your campaign. There are tiny terrors made massive, like the titan centipede and shipwrecker crab, alongside prehistoric gargantua like the colossal dire ape, immense tortoise, and giant brachiosaurus and tyrannosaurus. You will also find fantastic foes that fill the horizon, from planar predators like the astral leviathan and god-cursed zombie titan to an entire family of behemoths to ravage air, land, and sea, and the legendary tarrasque. As if these were not enough, we also bring you the biggest monster of all, the legendary linnorm Jormungandr, the Midgard Serpent! On top of 13 marvelous mythic monsters, we also present alternate rules for creature size and shape and a whole new combat climb system for your heroes to clamber and cling to their colossal opponents!