Punji Sticks are defense blocks used in protecting your home, valuables, and other goodies.
Placed Punji Sticks apply Slowness II to the player/mob when walked onto. They will also do damage, based on how many Punji Sticks are in one square, from one stick dealing 1/2 heart, to five sticks dealing 1 1/2 hearts of damage.
Despite the similarities to cactus, Punji Sticks will not erase dropped items, making them ideal for mob farms. Collection can be made easier with vanilla hoppers.
They are based on a defense used during the Vietnam War, of making a pit with sharpened bamboo stakes to impale those who fall in. The Tinker's construct Punji Stick appears to just be sharpened shoots that cause damage when walked on.