Towering, gangly creatures, serene like cattle, pick their way through the swamp on sharp spindly legs supporting a body that shrivels and bloats with blood consumption. They almost appear as leafless trees, their spear-like forelimbs hovering about the mud for minutes on end before striking at lightning speed, piercing fish, lizards and anything else they can find, before sucking them dry with the proboscis on their bodies and legs. When attacked or startled, they buzz into the air and swoop back, striking with many impaling legs. Their prey here is nearly fished out, so they migrate to find new grazing grounds. Instinct: To graze on blood

• Pierce them through
• Drive them into the muck
• Summon the herd