The crimson shambler resembles a bloody zombie. A creature that can see a crimson shambler must succeed on a DC 14 Intelligence (Nature or Religion) check to discern its true nature.

A creature that touches the shambler or hits it with an attack causes spores to spew out of the shambler in a 10-foot radius. Each creature in that area must succeed on a DC 10 Constitution saving throw or become diseased. Creatures immune to the poisoned condition are immune to this disease. The diseased creature’s lungs fill with the spores, which kill the creature in a number of days equal to 1d10 + the creature’s Constitution score, unless the disease is removed. One hour after infection, the creature becomes poisoned for the rest of the duration. After the creature dies, it rises as a crimson shambler, roaming for 1 week and attempting to infect any other creatures it encounters. At the end of the week, it collapses, its body fertilizing a new patch of crimson slime. A creature that succeeds on the saving throw is immune to the spores of all crimson shamblers and crimson slime for the next 24 hours.