First known venomous frogs stab with toxin-dripping lip spikes
Brazilian amphibians carry venoms more deadly than those of pit vipers
![yellow-skinned frog](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/08/080515_sm_venomous-frog_feat_free.jpg?fit=860%2C460&ssl=1)
WORST HEAD-BUTT When this yellow-skinned frog curls back its plump upper lip, bony spikes underneath stab toxins into foes.
Carlos Jared/Butantan Institute