Some more to strike from the list:
MCA1 - Monstrous Compendium Annual Volume One, 1994
Cat, Winged (Greater, Lesser) - do these differ from the tressym?
Laraken (FR16) - in Shining South
Spectral Wizard - does this differ from spectral mage in Magic of Faerun?
Tree, Death's Head (RLMC3) - Appears in Dragon #292
Tuyewara - already in CC
MCA2 - Monstrous Compendium Annual Volume Two, 1995
Elf, Winged ("Avariel") (DR51 as winged folk, CBE as avariel) - in Races of Faerun
Giant, Half-giant (Athasian) (DR173) - in Dragon #319
Hakeashar (FRE1, FR10, CoS); - in Lost Empires of Faerun (within nishruu)
Leucrotta, Greater (CoS) - does this differ from changesteed leucrotta in Waterdeep?
MCA3 - Monstrous Compendium Annual Volume Three, 1996
Belgoi - in Dungeon #111
Hag, Bheur (Spbd) - in Unapproachable East
Ixitxachitl, Ixzan (NtB) - in Lost Empires of Faerun
Spirit, Forest - Uthraki (Spbd) - in Unapproachable East
Spirit, Ice - Orglash (Spbd) - in Unapproachable East
Spirit, Rock - Thomil (Spbd) - in Unapproachable East
MCA4 - Monstrous Compendium Annual Volume Four, 1998
Mummy, Bog (DR238, Req) - WOTC's site
Snake - Sewerm - Serpent Kingdoms