Robert Thompson / Fly agaric (Amanita muscaria) Peatlands Park, County Armagh, Northern Ireland, October.

Chris Mattison / Yellow poison dart frog (Phyllobates terribilis) the world's most poisonous amphibian captive from northern South America.

Chris Mattison / Yellow poison dart frog (Phyllobates terribilis) the world's most poisonous amphibian captive from northern South America.

David Fleetham / Toxic spines of this Spotfin lionfish (Pterois antennata) Yap, Micronesia

Constantinos Petrinos / Black-spotted Porcupinefish (Diodon hystrix) poisonous species, Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Black-spotted Porcupinefish (Diodon hystrix) poisonous species, Lembeh Strait, North Sulawesi, Indonesia.

Chris Mattison / Natterjack toad (Epidalea calamita) close up of skin showing poison glands and vertebral stripe. Costa Vicentina National Park, Algarve, Portugal

MYN / Dirk Funhoff / Southern festoon butterfly (Zerynthia polyxena) caterpillar, Lorsch, Hessen, Germany. Meetyourneighbours.net project.

Doug Wechsler / Jack O'Lantern mushroom (Omphalotus illudens) poisonous, Fort Washington State Park, Pennsylvania, USA September

Will Watson / Monk's-hood (Aconitum napellus), Cadmore Brook, Tenbury Wells, Worcestershire, England, UK, May.

Alex Mustard / Lionfish (Pterois volitans) silhouettte of young fish swimming near the surface, Beacon Rock, Sha'ab Mahmood, Sinai, Egypt. Red Sea

Adrian Davies / White henbane (Hyoscamus albus) growing on wall in Trujillo, Extremadura, Spain. April 2016. Poisonous plant.