I Love the name of the Whack-a-mole ability.

Comillos: Comillos do drop treasure. However, it was only a few Hundred (1400 Was the Max.) or some Handgun ammo. 1 Green Herb was dropped.
Merchants have no treasure. They drop nothing. Unless, of course, your planning on looting the stands that the Merchants man.

Garrador: These guys have to be shot in the back, right? So why does he take a -2 Penalty when all my shots bounce off him from the front?
Illuminado Zealot (Red Fancy Cloak) also incorperated Scythes These guys were found in the Tower leading to the Salazar fight, and a few rooms before that. Also, one manned a Gattling Gun.

Krauser also uses Flash grenades, But only in form 1.