Follow the Spiders (2-5) - LEGO Harry Potter: Years 1-4
Year 2, Chapter 5
Once in control, shoot the mushrooms behind you. You need to shoot a total of 10 more similar mushrooms to unlock the Green Crest piece. Raise the stump and ride it so you can reach the upper ledge.
Then, clear the grass beside the tree with some boulders to finds some round lego pieces. Use WiLe to transform it to a raincloud. Lift it and let it rain down on the large tree. Midget treefolks will run down and build a ladder for Ron and Fang to climb up. Shoot the mushrooms here then have Fang dig the base of the large tree to bring it down for you to cross.
In the next part, shoot mushrooms and other stuff as usual. Remove the vines on the wooden bridge, then use WiLe to activate the brooms. Fly to the other side (ignore the silver gate for now).
After reaching the other side, use WiLe on the lego pieces to create a ramp for your allies to cross. Continue to the right to find a ladder. Pesky pixies will destroy it so another ladder will be created for you, courtesy of the guys earlier. After climbing the ladder, turn left to find a character token (Ron ~ Sweater). Continue to the right, then kill the pixies. Finally, use Fang to dig open the path to the next area. The final mushroom is found here so if you're short than 10, you may have missed some along the way.
After the scene, you'll be in another boss fight.
During this battle, free the student in peril trapped in the web.
The boss will keep spawning brown and purple spiders. It takes two hits to kill the ordinary brown spiders. As for the purple ones, press B to make them float, then hold B to make it spin. Remember that while you're spinning, you have a few seconds of invulnerability so don't hesitate to hold your ground and concentrate on spinning the spider then releasing it to damage the boss. Repeat this three times to finish this battle.
For the second sequence, take note of boxes that you can smash. Smashing all 5 of them will earn you a Red Crest piece. If you're using the car and a spider climbs up, press X to sound your horn and throw off the spiders. Continue your pace ahead from the boss and this sequence will end automatically after reaching the checkpoint.
Blue Crest piece - Cross the pond using the broom then fix the ramp. Stand on the ramp as shown in the screenshot to break the silver gate. Ride the frog and go through the gates to obtain the crest.
Professor Sinistra - After crossing the pond, open the dark cabinet.
Yellow Crest piece – During the boss fight, destroy the orb to the left using dark arts
Lucious Malfoy – During the boss fight as well, unlock the chest to the right
Just follow the ghost studs to trigger the next chapter.