Grenadier

A green-garbed goon with grenades. Still less of a pain than the Grunt.

Strategy
To expand on the previous point, the Grenadier technically inflicts more damage per hit, but does not shoot as quickly, consistently or at as great a distance as the Grunt. Furthermore, their grenades are slow and easy to dodge.

They are best dispatched from medium to long range with Crossbow variants or explosives. While a Shotgun or Autoloader could kill one if all the pellets connect, the closeness necessary to do so gives the player less time to avoid an oncoming grenade.