Story Scroll: The Fire Vipers of Doom
When you reach Perilous Plateau, took a right from Sharpfin and head up the slope to find this scroll.
Rubber Ducky (1/5)
After encountering the Boom Bosses, bust up the boxes in the back of the area. Follow this hidden path to find the first ducky.
Rubber Ducky (2/5)
You'll spot this as you approach the second platform with a rotating electrical rod. Proceed through, then take a left at the next platform to reach it.
Rubber Ducky (3/5)
Take a left before exiting Arid Cave to grab this off of a ledge.
Rubber Ducky (4/5)
Before destroying the second crystal, continue up the platforms past the screws. You'll find this a little higher up.
Legendary Treasure: Crystal Fire Heart
When you land in Underground Lake, you'll be near a dual Undead/Earth Elemental Gate. Use a Swap Force character with these elements (or use appropriate Skylanders, if you're playing co-op) to open the way. Complete the challenge inside to earn this.
Rubber Ducky (5/5)
Take a left after crossing the long green bridge in Serene Walkway. This leads to the last duck.