Done using the Monster Advancer program, not checked yet. Not sure why it ended up having 74HD.
Zombie Tyrannosaurus CR 8
Always Neutral Evil Gargantuan Undead
Init +0
AC 13 FF 13 Touch 6 (-4 size, +7 natural)
HD: 74
HP: 484 (74d12+3)
Saves: Fort +12 Ref +12 Will +20
Speed 40ft
Base Atk +18 Grp +40
Attack: Slam +24 3d6+10
Attack: Bite +24 4d6+15 (19-20/x2)
Grapple Attack: Grapple +40
Grapple Attack: Swallow Whole +40 3d8+10
Full Attack: Bite +24 4d6+15 (19-20/x2)
Space 20 ft. (4 squares) Reach 15 ft. (3 squares)
Abilities Str 30(+10) Dex 10(+0) Con — Int — Wis 10(+0) Cha 1(-5)
Stat Points Gained From Advancement: 14
Total Feats: 25
Feats: Toughness
Single Actions Only(Ex): Zombies have poor reflexes and can perform only a single move action or attack action each round. A zombie can move up to its speed and attack in the same round, but only if it attempts to charge.