Spike Beasts are a dangerous enemy in Warrior Within.
There were once packs of feral wolves that inhabited the Island of Time, and the Empress of Time decided to add them to her ranks of minions. Using arcane magic, she transformed them into four-legged monstrosities, covered entirely in protective spikes.
These beasts torment the Prince by attacking in packs, and leaping at him. They can also walk on walls. Upon death however, they have one more method of offense: the ability to explode, damaging anyone or anything nearby.