“Don’t Lick the Worms.” Hammerhead Flatworms Are Invasive and Toxic — They Might Be In Your Backyard

Hammerhead flatworms are invasive and toxic. These worms, native to Asia, contain neurotoxins similar to those in pufferfish.
The Weather Network on MSN

Don't kill it: Toxic hammerhead worms are back this spring

Cooler temperatures have now forced the worms into hiding here in Canada, but in other parts of the continent they are thriving and triggering local warnings.