Primal Pilum

+3 Javelin, Range 120 ft
2d8+3+STR Piercing + 2d12 Fire + 2d10 Cold
This weapon scores a critical hit on 18-20
On hitting a target the javelin erupts, sprouting
thorny vines in all directions along the ground in
a 30 ft radius. This lasts for 10 minutes, the area
is difficult terrain and when a creature moves
within the area, it takes 4d4 piercing damage for
every 5 feet it travels.
The Pilum is destroyed after triggering this.