Even though they would be quite effective for the Dragon cause, Scarers remained un-involved in the Dragon Rebellion.
To Note: Stats from The Incomplete Book of Dragons differ from those given in the info box found in How to Break a Dragon's Heart.
Scarers very much look like dragonized bats. They appear to be black in color with purple wing membranes.
The Scarer's sense of smell is excellent, and can detect fear-induced adrenaline in a victim's bloodstream.
Scarers are small, blind, and have poor hearing.
Traveling in "thick, cloudy black swarms called flutters", Scarers will flit about at night sniffing for a fearful victim. Because their senses are otherwise dull, they will crawl all over the victim sniffing. This causes even more fear-induced adrenaline in the hapless victim. Once a victim is identified, Scarers will drink their blood containing the prized adrenaline.
Scarers are described in this references book.