Cave Spider
The last boss of the cycle, at 4,500 metres in the Mist Caves. She hangs from the cave roof on a single thread, red eyes glowing, and keeps pace ahead of you.

What she does
Two attacks, in turn. She spits webs in a lob, with red dots showing the arc. And every third attack she drops: she stops above a spot ahead, her shadow darkens on the ground with a red !, and as the ninja arrives she drops down her thread to bite.
How to beat her
Send her webs back. A line across the dots, tilted toward her, bounces the web into her. Five hits and she falls on her back and curls up.
For the drop, draw a roof above the spot where her shadow falls. She hits the line instead of the ninja and is stunned for a moment, spinning stars and all.
Best ink
Pen or steel for returns. Fire burns a web away, which is safe but doesn't hurt her. Any ink makes a roof for her drop, except fire, which she drops straight through.
Her angry phase
After the first hit she sends two spiderlings scuttling along the ground at the ninja, like the desert scorpions. Bridge over them, or burn or crush them with fire or steel.
She also shakes the cave: a cave-in brings stalactites down on the path ahead. A roof over the ninja catches them.
Reward
50 coins, points and, the first time, the Web cutter badge. After her, the run starts its next lap with the Giant Archer in Bamboo Valley.