These are not named mobs, and drop no special items. However, these can be 'place holders' for named mobs (such as the Silverflank Shiverback, which drops the mnk/bst haste belt mentioned above), depending on where they spawn (the mob in the picture is, in fact, in a 'named' spawning location).
These are not overly tough mobs for the zone, but do have a ton of hitpoints (like 20,000+).