Disease Mimicry – The ability to be a disease.
Sublime (Marvel) is a sentient bacterium (New X-Men #154).
Wildstorm Spotlight – Majestic #1 (2000) introduces the reader to a hyper-intelligent strain of syphilis known as the Simberleen.
Metaphysique #1 (Eclipse)
Morticoccus Virus – Kamandi #10 (DC)
Stygian Virus – Countdown to Adventure V1 #7 (DC)