Mora is a giant spider who resides in the Mouldwood Depths along with her many children. When the Spirit Willow lost her light, Mora sealed the entrance to their domain to protect herself and her children, but the Decay affected the darkness within Mouldwood. This caused Mora and her children to become corrupted, resulting in Mora becoming tainted with corrupted fungus that turned her hostile, stealing the Eyes of the Forest for herself.
Mora is a giant black spider with eight legs. She has yellow glowing fungus growing on her head, body, and legs. Before and during the boss battle with her her eyes are pure yellow without pupils, but after the battle her eyes turn clear and black, signifying the clearing of the corruption in her mind.