WARNING! This episode will freak you out. Did you know that almost half of all life on earth is parasitic? Join us for an eerie video hosted by Hank Green and learn about four of the creepiest parasites on Earth. Go to http://Brilliant.org/SciShow to try their Beautiful Geometry course. The first 200 subscribers get 20% off an annual Premium subscription. Hosted by: Hank Green SciShow has a spinoff podcast! It's called SciShow Tangents. Check it out at http://www.scishowtangents.org/ ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever: Adam Brainard, Greg, Alex Hackman, Sam Lutfi, D.A. Noe, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Patrick D. Ashmore, charles george, Kevin Bealer, Chris Peters ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com/ Instagram: http://instagram.com/thescishow ---------- Sources: https://www.otago.ac.nz/parasitegroup/PDF%20papers/Poulin2014-IJP.pdf https://www.researchgate.net/publication/300095919_Effect_of_the_parasitic_isopod_Anilocra_apogonae_Cymothoidae_on_the_growth_condition_reproduction_and_survival_of_cardinal_fish_Apogonidae https://repositories.lib.utexas.edu/handle/2152/ETD-UT-2012-08-6285 https://www.researchgate.net/profile/Denham_Parker/publication/257377303_The_tongue-replacing_isopod_Cymothoa_borbonica_reduces_the_growth_of_largespot_pompano_Trachinotus_botla/links/0c960533d44dfbd0d1000000.pdf http://aquaticcommons.org/8583/1/NG_62_2003_Williams&Bunkley-Williams_Fish-parasitic_isopods.pdf https://www.researchgate.net/publication/319913453_First_record_of_the_snapper-choking_isopod_Cymothoa_excisa_Isopoda_Cymothoidae_parasitizing_invasive_lionfish_Pterois_volitans_Scorpaeniformes_Scorpaenidae http://people.oregonstate.edu/~blaustea/pdfs/JohnsonBlausteinEcoMonographs.pdf https://www.researchgate.net/publication/8211765_Review_of_the_Trematode_Genus_Ribeiroia_Psilostomidae_Ecology_Life_History_and_Pathogenesis_with_Special_Emphasis_on_the_Amphibian_Malformation_Problem https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/jzo.12094https://www.cambridge.org/core/journals/journal-of-the-marine-biological-association-of-the-united-kingdom/article/biology-and-life-cycle-of-the-rhizocephala-cirripedia/11C2E47CABCABB175F4C49B1393BE125 https://www.sciencedirect.com/science/article/pii/S138511011530037X https://nph.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-8137.2002.00396.x https://www.harvardmagazine.com/2017/03/colossal-blossom https://bulbapedia.bulbagarden.net/wiki/Vileplume_(Pok%C3%A9mon) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3460754/ Image Sources: https://commons.wikimedia.org/wiki/File:Amphiprion_clarkii_-_Cymothoa_exigua_(28999213532).jpg https://commons.wikimedia.org/wiki/File:Cymothoa_exigua_parassita_Lithognathus_mormyrus.JPG https://commons.wikimedia.org/wiki/File:Annual_report_of_the_Game_and_Fisheries_Department_of_Ontario,_1921-34%22_(19176931660).jpg https://commons.wikimedia.org/wiki/File:P._regilla_with_parasite-induced_limb_malformation.png https://commons.wikimedia.org/wiki/File:Leucochloridium.ogv https://commons.wikimedia.org/wiki/File:Three-legged_frog_(Rana_temporaria)_(8137866910).jpg https://commons.wikimedia.org/wiki/File:Greenfrog_life_stages.svg https://commons.wikimedia.org/wiki/File:Sacculina_carcini.jpg https://www.eurekalert.org/multimedia/pub/144794.php?from=363929 https://commons.wikimedia.org/wiki/File:Haeckel_Sacculina.jpg https://commons.wikimedia.org/wiki/File:Wurzelkrebs-drawing.jpg https://commons.wikimedia.org/wiki/File:Xantho_poressa_2009_G1.jpg https://commons.wikimedia.org/wiki/File:Ah,_Rafflesia!_(11967075415).jpg https://commons.wikimedia.org/wiki/File:Rafflesia_zollingeriana_Kds.jpg https://commons.wikimedia.org/wiki/File:Rafflesia-Bud_on_Liana.jpg https://commons.wikimedia.org/wiki/File:This_Rafflesia_is_already_showing_signs_of_wilting_(11967407133).jpg https://commons.wikimedia.org/wiki/File:Stamps_of_Indonesia,_029-08.jpg https://commons.wikimedia.org/wiki/File:Rafflesia_arnoldii_cycle.jpg