A creeper can use Stealth while moving at full speed without penalty. A creeper can use Stealth to move without cover as long as observers are not explicitly facing its direction, though it takes a -5 penalty, which increases by -5 for every round spent sneaking in plain sight like this.
A creeper will not willingly travel within ten feet of a cat.
As a full-round action, a creeper may burst in a 15ft-radius blast. This kills the creeper and inflicts 5d6 dmg [B, 🔥] to all adjacent. All within the radius take 3d6 dmg [B], Reflex DC15 halves (this stacks with the close-range damage). The explosion creates a crater with a 15ft-radius: 15ft deep at the center and raising by 5ft for every square outward. The crater is treated as difficult terrain. This crater is negated if the explosion takes place underwater, and the radius is decreased to 5ft if the creeper is standing on strong stone.
A creeper struck by lightning or dealt at least 10 electricity damage has its blast heightened. The blast now possesses a 25ft-radius and inflicts 8d6 dmg [B, ⚡] to all within 10ft of the creeper. All within the radius take 3d6 dmg [B, 🔥]. Reflex DC19 halves. This affects the crater likewise.
Created by Kobold Cleaver in this thread on Paizo forums, thanks a ton! I toned it down juuuust a bit. Obligatory sound effect.
Originally known only within the depths of the Darklands, these "creepers" have become more and more prevalent in dwarven mines and kobold warrens. Their origins are unknown—they seem to know no master, and indeed don't even appear particularly malicious. Some speculate that they were created in drow fleshwarping experiments, but drow, having suffered great losses from the awful monsters, furiously deny this.
Sages tend to put creepers in roughly the same realm as rust monsters and disenchanters: one of those nasty monsters one just tries to avoid. But creepers don't make that easy. They don't appear to be fully aware of what comes after the "boom", but they really, really want it. And they want people to notice.
Those few who have managed to communicate with creepers have said that, above all, above even their self-destructive instincts, the creatures appear to be intensely lonely.