As soon after the level starts, make your way through and you'll find your first armored druid.
Shortly afterwards, you will find a room with 4 of them in a diagonal line.
Hug the wall to the left and you will see a small alcove, this is perfect for lining up your run.
Turn Spyro to face down the line of druids and CHARGE!
You MUST hit all 4 in ONE charge run!