Save The Purple Chompies! is the Heroic Challenge provided by Drobot in both Skylanders: Spyro's Adventure and Skylanders: Giants, and takes place in the mines. This level is rated as being very tough. The player must clear out a large number of invasive Green Chompies (100 in the PlayStation 3, Xbox 360 and PC/MAC versions; 55 for the Wii version and for all versions in Giants) but cannot destroy more than one of the beneficial Purple Chompies in two minutes and thirty seconds or else they fail the challenge. This challenge is quite possibly one of the most difficult in the game. Unlike the Green Chompies, the Purple Chompies will latch on and drain health at an alarming rate, with attempts to shake them off ending up killing them, which counts against you. The Wii version is less difficult than the other versions of the game; because the Purple Chompies sparkle, making them easier to distinguish from Green Chompies at a far away distance.
Upon completion, the Skylander gains a permanent +8 Bonus to Speed (+4 in Giants)
Clearing the Challenge
This is a difficult challenge, partly because the Purple Chompies are aggressive, but also because Skylanders will still auto-target them with certain attacks if they are pointed in their direction. Precise, simple attacks are best for this challenge and it might prove insurmountable to a Skylander who lacks an attack that can provide such finesse. Projectile attacks that explode or pierce through enemies could be bad (such as Gill Grunt's Piercing Harpoons or Stump Smash's Pollen Plume) because they may also hit the Purple Chompies. Attacks that leave behind damaging forces are also bad since the Purple Chompies will gladly waddle or leap into them and die (like Eruptor's Fiery Remains or Dino-Rang's Stonefist Trap Funeral). The best thing to do is run past the Purple Chompies and focus on the clusters of Green Chompies as there are several areas that contain nothing but the green ones. Just make sure you know what you are hitting whenever you attack and only use attacks that you can control the target of. Thankfully, there are a few more Green Chompies in the level than you need so if one or two green ones get clustered too close to some purple ones, you can just skip them.
It is impossible to do this as Giants (or at least extremely hard) as they stomp them.