Caltrops, Vicious

Source Goblins of Golarion

These specially modified caltrops have clusters of needle-sharp spines that are slightly longer and more brittle than those on normal caltrops. Like standard caltrops, a 2-pound bag of vicious caltrops covers a 5-foot-square area. Vicious caltrops work just like normal caltrops, save that they have an attack bonus of +4, do 1d2 points of damage, and require a DC 20 Heal check to fully treat.