Anime/C

Ca

 * Captain Future - EP24: A criminal shinks himself and attacks a micro-universe. Captain Future shrinks himself too in order to catch that criminal. There are brief para-GTS scenes where Joan Randall (a blonde woman) and another women (green-haired) interact with the shrunken ones.
 * Cardcaptor Sakura: A 10-years old girl must capture magic card to protect the world from a catastrophe. There are 2 card that can shift the size: "The Big" and "The Little". The original series has 4 episodes with relative giantess issue.
 * This article includes its sequel Cardcaptor Sakura: Clear Card. It only has 1 episode with GTS issue.

Ce

 * Cells at Work! - EP10: A bunch of staphylococcus aureus fused together to become bigger.

Co

 * Colorful - EP12: "Color 12". Based on Colorful - CH052 (manga version), this episode focuses on a giant girl dressed as a schoolgirl, who emerges from the sea and attacks a city.
 * Cosmic Publisher - Alice in Wonderland: This is an animation that you can only get (by buying) at Amazon (here). Although the DVD cover says "Father Long Legs", this DVD has three animations, one of which is about Alice in Wonderland.