Juggle a rock 5 times without it hitting the ground
Ori and the Blind Forest JUGGLE MASTER Achievement Guide
One of the only rocks in the game is in Sorrow Pass near the end of the game. Progress through the left side of Sorrow Pass and you will find a rock. You have to use your bash to get it to an open space.
Stand next to it and use your bash to throw it in the air. Catch it with your bash move again before it touches the ground and juggle the rock this way 5 times.