Cryptid, prehistoric creature, myth - you decide.  This is the Legend of the Thunderbird.

Sources

https://www.cuyamungueinstitute.com/articles-and-news/thunderbird-a-symbol-of-power-strength-and-nobility/ https://www.birdnote.org/listen/shows/myth-thunderbird https://mysteriesofcanada.com/newfoundland/thunderbird-a-canadian-legend/ https://cryptidz.fandom.com/wiki/Thunderbird https://www.atlasobscura.com/articles/thunderbird-cryptid-ocker https://cryptozoologycryptids.fandom.com/wiki/Thunderbird#Photo https://en.wikipedia.org/wiki/Thunderbird_(mythology) https://www.paranormalcatalog.net/cryptids/thunderbird-cryptid-bird-with-a-70ft-wingspan https://pawilds.com/legend-of-the-thunderbird/ https://www.treasurenet.com/threads/legendary-thunderbird-photo.50497/ https://cryptomundo.com/cryptozoology/thunderbirds/ https://cryptomundo.com/eyewitness-accounts/alaska-thunderbird-sighted/ https://www.juneauempire.com/life/impossibly-large-bird-spotted-in-mendenhall-valley/ https://en.wikipedia.org/wiki/Talk%3AThunderbird_(cryptozoology) https://www.historydefined.net/thunderbird/ https://www.native-languages.org/thunderbird.htm https://www.amazon.com/exec/obidos/ASIN/0140547924/natilangofthe-20 https://www.britannica.com/topic/thunderbird-mythological-bird https://www.historicmysteries.com/myths-legends/thunderbird/22913/ https://spiritsofthewestcoast.com/collections/the-thunderbird-symbol https://www.audubon.org/news/-rulers-upper-realm-thunderbirds-are-powerful-native-spirits https://en.wikipedia.org/wiki/Thunderbird_and_Whale https://en.wikipedia.org/wiki/Quileute https://web.archive.org/web/20070104171450/http://www.ess.washington.edu/SEIS/PNSN/HIST_CAT/STORIES/welcome.html https://web.archive.org/web/20061212145252/http://www.pnsn.org/HIST_CAT/SRL76-2Ludwin.pdf https://indigenouspeoplenet.wordpress.com/2022/11/22/mythologies-of-the-thunderbird/ https://pnsn.org/outreach/native-american-stories/thunderbird-and-whale/thunderbird-and-whale-stories/the-thunder-bird-a-tillamook-legend https://a-z-animals.com/blog/what-were-the-largest-flying-dinosaurs/ https://en.wikipedia.org/wiki/Teratornithidae https://www.atlasobscura.com/places/ghost-forest-of-copalis https://www.wizardingworld.com/fact-file/creatures/thunderbird https://harrypotter.fandom.com/wiki/Ilvermorny_School_of_Witchcraft_and_Wizardry#Houses