Caboj's Venomous Defence

After preparing a trap, whether for defence, hunting or ambush, you spend 10 minutes conjuring a fey spirit which assumes the form of a snake, spider or other venomous beast then intwines itself into the trap. 

Upon the trap being triggered, the beast attacks the creature that triggered it dealing 1d8 poison damage. In addition the target must make a constitution saving throw or be poisoned for 10 minutes.

After being triggered the conjured beast disipates.