Coronic acid
Coronic acid was a type of acid that was harmful to Sontarans, causing damage to their bodies and their Sontaran space armour, typically killing them on contact (although Group Marshal Stike of the Ninth Sontaran Battle Group was able to survive this and many other injuries). The substance produced large showers of white sparks, similar to burning magnesium.
It was used against them in 1985 by Chessene of the Franzine Grig and it managed to kill Major Varl of the Ninth Sontaran Battle Group (TV: The Two Doctors) and in 2371 by Raghi defence forces. (PROSE: Lords of the Storm)
Before killing his victims, Zebulon Pryce would use coronic acid to slowly remove the flesh from their bones while leaving the nerves and circulatory system intact. (PROSE: Original Sin)
