Actually, Khisanth or Onyx, was a BLACK dragon breathing acid, not a shadowdragon. Grimwolf was a human who got himself turned into a shadowdragon, though! Raistlin was nearly killed by Khisanth, and his nephew Palin Majere knew Grimwolf.
(And, in my own novel, the Black Robe Lundarquarius Eclipse was in reality a shadowdragon trapped in elf form, by the same evil mage (Danvil Felcraft) who trapped Jasryn into a human boy from a silver dragon hatchling.) Now, if ONLY the editors at WoTC would consent to give me a publishing contract...hint, hint!