"Planet of the Spiders" in progress...
"Planet of the Spiders" was the last episode of Jon Pertwee's run on Doctor Who. The Third Doctor would eventually die from radiation poisoning on Metebelis 3 (the eponymous planet) and regenerate into Tom Baker's Fourth Doctor.

In this charity illustration (still in progress) the Great One, a giant spider craving absolute power, wants the Metebelis crystal that the Doctor holds. Needless to say, she does not succeed.

Almost finished this one: I need to tighten it up, maybe add some "sparkles" in the background, showing the rest of the crystals in the spider's lair. Also, I can't resist adding just a little bit of color and making the crystal the Doctor is holding blue.