To simplify matters, it seems that Taunt just forces monster to use their A1/A2 attacks as listed in the MPQ files. A1/A2 attacks are what most players call "normal attacks", since they both (always?) use a monster's normal swing, thrust, or shoot (if it can't melee) animation in contrast to some other casting or special animations. I have not examined monster attacks and the AI that drives them in detail, but it looks like all A1/A2 attacks have a physical component, often carry extra elemental damage, and occasionally have a special ability attached to them. Since these special abilities are an integral part of a monster's normal attack, they will never be shutdown by Taunt. Below is a list of such abilities I have noticed while taking a quick look at the MPQ files:
- Wraith and Gloam type monsters all have a chance to drain mana with their A1 attacks
- Mosquito and Swarm type monsters all have a chance to drain stamina with their A1 attacks
- Tree Hulk type monsters can always stun with their A2 attacks
- Snow Yeti type monsters can always stun with their A1 attacks
- Moon Clans can drain mana as guest monsters with their A1 attacks
- Blood Hawks can steal life as guest monsters with their A1 attacks
- Black Raptors can drain mana as guest monsters with their A1 attacks
Looking at the monster AI files, there may be a slight complication in that some monsters could be restricted to only use their A1 attacks when taunted. My guess is that any monters without a "att1/att2?" check in their "monai.txt" entry can only use their A1 attacks when taunted (they use the "attack?" check instead), and this would affect all but the Tree Hulk and Snow Yeti type monsters listed above (e.g. a Wraith will never use an A2 attack, so it will always drain mana with its A1 attack when taunted).
If a special ability, defined broadly (if I may speculate) as any action not using a monster's normal attack animation, is not included in the list above, then it can probably be interrupted by Taunt. This would specifically include any casting or ranged attack from a monster capable of a melee attack, which covers most of Occhidiangela's list above (I think Finger Mages can only drain mana with a ranged attack though). If a monster is not capable of performing a normal melee attack, it will then be forced to approach the taunting Barbarian before executing it's normal missile attack at point blank range.
- Wraith and Gloam type monsters all have a chance to drain mana with their A1 attacks
- Mosquito and Swarm type monsters all have a chance to drain stamina with their A1 attacks
- Tree Hulk type monsters can always stun with their A2 attacks
- Snow Yeti type monsters can always stun with their A1 attacks
- Moon Clans can drain mana as guest monsters with their A1 attacks
- Blood Hawks can steal life as guest monsters with their A1 attacks
- Black Raptors can drain mana as guest monsters with their A1 attacks
Looking at the monster AI files, there may be a slight complication in that some monsters could be restricted to only use their A1 attacks when taunted. My guess is that any monters without a "att1/att2?" check in their "monai.txt" entry can only use their A1 attacks when taunted (they use the "attack?" check instead), and this would affect all but the Tree Hulk and Snow Yeti type monsters listed above (e.g. a Wraith will never use an A2 attack, so it will always drain mana with its A1 attack when taunted).
If a special ability, defined broadly (if I may speculate) as any action not using a monster's normal attack animation, is not included in the list above, then it can probably be interrupted by Taunt. This would specifically include any casting or ranged attack from a monster capable of a melee attack, which covers most of Occhidiangela's list above (I think Finger Mages can only drain mana with a ranged attack though). If a monster is not capable of performing a normal melee attack, it will then be forced to approach the taunting Barbarian before executing it's normal missile attack at point blank range.