肿头龙是一个谜一般的生物。它跟岛上很多生物一样,是十分被动（甚至友好）的食草动物。但是它又是岛上我遇到过的最危险的食草动物之一。它的冲刺头撞是是绝对力量的完美展现，这个技能以比你想象更快的速度杀死敌人。 虽然一般来说肿头龙都是温顺的，但它依然十分易怒。它在战斗或是逃跑的选择中似乎总是选择战斗！ 当肿头龙被攻击后，它会变得非常有攻击性。 此外，它还会及其快速的冲刺，因此从一头愤怒的肿头龙面前逃走是十分困难的。
Common name: Pachy
Species: Pachycephalosaurus leniproelia
Time: Late Cretaceous
Pachycephalosaurus is a bit of a conundrum. It is a very passive (even friendly) herbivore, common to much of the Island. At the same time, it is one of the most dangerous herbivores that I have yet encountered on the Island. Its charging headbutt is a display of sheer physical power, and can kill much more quickly than you might think. While Pachycephalosaurus is generally friendly, it has a short temper. Its fight-or-flight response always seems to choose "fight!" The Pachy becomes extremely aggressive once attacked. Additionally, it is an incredibly fast sprinter, so escaping from an enraged Pachy is very difficult.
Pachycephalosaurus is an excellent battle-mount for those who want to ride a smaller, nimble combatant into the fray. Because of its particular musculature, it cannot effectively carry large quantities of resources. It can, however, move with brief magnificent bursts of speed, and its headbutt is simply devastating.