[BoberJones]

 Reproduce:
1.) Have Mercs
2.) Turn off Total Control
3.) Get into battle
4.) Drag your 'attack' from the menu to the hot bar
5.) Hold the hot bar key with attack while your Merc is in total control

Example: GIF
This can make snakes shoot two snake heads, and also make some mobs attack 2-4 times, 2 if they moved, 4 if they didn't

(posting for another because they don't have a forum post)