I've been doing some brainstorming for a flying megabeast.

A hawk with a scorpion tail. Designed to make hunting easier for 3rd world countries, experiment escaped when  the Infection broke out and they've all gone feral.

Poison should not kill directly, but make it considerably easier for a third party to kill.
- Instant Blindness
- Instant impairment of hearing
- Mild Nausea