Rayman Origins

This is actually a pretty easy achievement. I'll describe a thrid method, I found by playing through a game.

When you become small you get the the dash-attacks. Just run into the water and right BEFORE touching it, dash to the right/left and above again. The piranha won't be able to attack you while you do the dash attack. Get back on surface, achievement unlocked.

Piranha's can be found in the first levels of the 'Gourmet Land' world, although I recommend trying it on the second level, since in the first level you'll have to chase a mermaid first.

I later found out I wasn't the first to discover this, check out this video on youtube if you're having trouble with the text-based tutorial.

This achievement can be earned EARLEST in the third world "Gourmand Land" on the first level "Polar Pursuit." There are 2 method of earning this achievement.

1) On the 2nd stage of the level you will see the water change to a blood red color. There will also be deadly piranhas swimming frantically after you. If you have a good running flow you will be ahead of the chasing piranhas enough to jump in and out of the water without being attacked.

2) If you have a second controller, have the pawn character jump in the water to be a decoy and the piranhas will go for him. Then jump in and out of the water and the achievement will pop.

Either method will net you this 15G achievement!

(I have the achievement earned when I typed this, I just haven't forced the scan yet.)

For this achievement you need to find the red water with the Piranha's following you. I did this in world 3.

Simple to do, just crush (jump then LS down + X) so you plunge to the bottom so they can't nibble you. When you start to come back up simply tap A a few times to make sure you get out before they get you first.

A good way to do this is to use a second controller. Just distract them with the second controller, and go in the water with the first controller ( the one with the profile you want the achievement on ) and get out. The achievement should pop ! ;)

I got this achievement accidentally by taking advantage of the moment of invincibility you get after taking damage. In Polar Panic, in the section before the last cage, there is a large gold medallion tucked away within a bunch of yellow spike enemies against an ice pillar. It's on the main path. You can't miss it. I was trying to jump to the medallion when I hit the spikes, losing my heart and dropping into the piranha pond. Since you are invincible after taking the hit, just jump out and the achievement is yours!