Here is a lionfish. According to my ehem, research, the lionfish is one of the most venomous fish in the entire world. While their long dorsal fins are venomous, they are not really life-threatening to humans, although being stung by one can be extremely painful and may cause headaches, vomiting and breathing difficulties.
There's something so... grandfatherly about them, no? Their sad eyes and droopy jaws. They look ancient, like a creature from another time.