Pandaren Brewmaster's spirits (Storm, Earth and Fire) actually have Death and Dissipate animations; they're just named "bla".
Kodo Beast has two stand animations ("oldStand" and "oldStand - 2") in which the Orc rider doesn't strike the drums.
Infernal Contraption has a "blaSpell" animation.
Hippogryph Rider has an unnamed animation in which it falls to the ground.
Destroyer's portrait has one more talk animation, "PortraitTalkAlternateNotUsed - 1".
Portrait of the Spider Crab critter has a talk animation that doesn't work because the word Portrait was misspelled as "Portriat".
Ice Troll, Forest Troll Trapper and Dark Troll Trapper have "oldSpell -Berserk".
Sea Giants have an additional "HoldWalkSwim" animation, in which they are not completely submerged.
Alchemist has a "Monkey" animation, in which the ogre jumps up and down.
Tree Of Life still has a "hold" animation that was used in Warcraft 3 Beta to channel/maintain the Entangled Gold Mine, while mining gold from it.