|“||They say that there's a vicious dinosaur living around here. Don't try to take that monster head-on. Just run for your life!”|
|— Daroach • Kirby Mass Attack|
Freezy Rex's appearance is based on a tyrannosaurus rex, but its chin is greatly exaggerated. Its body appears to be made from globular blue ice crystals. Its hands and feet each have a pair of claws.
Freezy Rex appears exclusively in Stage 9 of Dedede Resort. The Kirbys hit a switch and fall into the dinosaur's icy realm. This enrages the beast, who smashes down a wall, roars, and chases them. This lasts through the entirety of the stage, as the colossal dinosaur crashes indiscriminately through all terrain and obstacles. The beast is invincible and cannot be defeated, not even under the effects of Invincible Candy.
Any Kirby that touches Freezy Rex while it is moving takes damage, and enemies that make contact are instantly defeated. In addition to the constant threat of its pursuit, the foe has two attacks: It can stop in place to inhale, then blow freezing breath horizontally. Any Kirby hit by this is frozen; the player has only a few seconds to tap him out of the ice before he is KO'd. Freezy Rex occasionally bellows before sprinting across the screen. When it does this, the player should cluster the Kirbys on the rightmost side of the screen—Freezy Rex's chin collides with a steel beam mounted in the ceiling, knocking the monster back before it can trample the heroes.
Near the end of the level, the Kirbys find a switch they can rapidly hit. If they are too slow, Freezy Rex grinds through the three beams and tramples the group, KOing it. Successfully hitting the switch drops the floor out from under the behemoth, causing it to fall into a deep chasm. It is then covered by debris from overhead as part of the cave collapses, and the Kirbys can walk over it and escape.
- Despite being a mid-boss, Freezy Rex does not appear in Survival Rush. This may be because its encounter takes up an entire stage, and it is not fought directly.
- Freezy Rex is one of the few characters in the Kirby series capable of defeating Gordos.
- The theme when encountering Freezy Rex, called "Icy Realm," is a rearrangement of the Frozen Hillside stage theme from Kirby Air Ride.
- Freezy Rex's Japanese name, Blizzardon, may be a reference to the Pokémon Charizard's Japanese name, Lizardon.