- 50 Foot Congo Snake
- 52-Hertz Whale
- A-Mi-Kuk
- Aatxe
- Abada
- Abaia
- Abarimon
- Abath
- Abatwa
- Abbagoochie
- Aberdeen Carcass
- Aberdeen Wildman
- Abnauayu
- Abominable (2006)
- Abominable Swamp Slob
- Abura Akago
- Abura Sumashi
- Abyssal Rainbow Gar
- Achiyalabopa
- Achlis
- Acurini white Amazonian Indians
- Adam-Dzhapais
- Adam-ayu
- Adar Llwch Gwin
- Adaro
- Adjule
- Adlet
- Adze
- Afa
- Afanc
- Afonya
- African Peacock
- African capybara
- Aglebemu
- Agogwe
- Agrios Anthropos
- Agropelter
- Agta
- Ah-Een-Meelow
- Ahool
- Ahuitzotl
- Aiatar
- Aidakhar
- Aigamuxa
- Air Massif's lizard
- Air Rods
- Airborne Frogman
- Aitvaras
- Akamataa
- Akaname
- Akateko
- Akerbeltz
- Akhlut
- Akita Lion
- Akkorokamui
- Aksar
- Akshayavat
- Akuchu
- Akurra
- Al-Abstergo (The Hat Man / Abstergo Man)
- Alaska Monsters
- Alaskan Giant Polar Bear
- Albatwitch
- Alderney Yellow Light
- Algerian Hairy Viper
- Alicanto
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- Alien Encounter Timeline
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- Alien Sightings of Canada
- Alien Sightings of China
- Alien Sightings of Croatia
- Alien Sightings of France
- Alien Sightings of India
- Alien Sightings of Mexico
- Alien Sightings of New Zealand
- Alien Sightings of Norway
- Alien Sightings of Russia
- Alien Sightings of Spain
- Alien Sightings of Sweden
- Alien Sightings of Thailand
- Alien Sightings of the Philippines
- Alien Spores
- Alien sightings of Portugal
- Aliens
- Alihuen
- Alkali Lake Monster
- Allegewi
- Allier River Monster
- Almas
- Almond Eyes
- Alovot
- Altamaha-ha
- Alula Whale
- Amabie
- Amaguq
- Amalanhig
- Amali
- Amarillo Creature
- Amarok
- Amassie
- Ambize
- Amemasu
- American Chupacabra
- American Falls Cryptid
- American Hyena
- American Lions
- Amhuluk
- Amikuk
- Amomongo
- Amphisbaena
- Anchimallen
- Ancient Aliens
- Ancient Astronauts
- Ancient of Genes
- Andaman Wood Owl
- Andean Wolf
- Angeoa
- Anguila Peluda
- Animal Planet adventure sets
- Animal X
- Animal from Karen Hills
- Anjing Ajak
- Anka
- Ankylosaur of Katsuro Desert
- Antarctic Godzilla
- Antarctic Long-Finned Whale
- Antarctic Sea Spider
- Antarctic Spider
- Antmen
- Ao Ao
- Aoyin
- Apollo 8 Space Squids
- Appalachian Chupacabra
- Apula Robot
- Aquatic cattle in Chilean folklore
- Arabian Flying Snakes
- Araǵanaqlta’a
- Arboreal Abomination
- Area 51
- Argentina Werewolf
- Argentinian Dog of Death
- Arica Monster
- Ariel School Aliens
- Arizona Jaguar
- Arkansas Gowrow
- Arkansas Snipe
- Armadillo Man
- Aron Prod.
- Arre River Monster
- Artrellia
- Arzamassian Monster
- Asahhie
- Ashuaps
- Asian Mermaids (Matsyāṅganā and Ningyo)
- Aspidochelone
- Assie
- Aswang
- Ataka Carcass
- Atami Stegosaurus
- Atlantic Ocean Winged Abomination
- Atlas Bear
- Atmospheric Beasts
- Atmospheric Jellyfish
- Audubon's Unidentified Birds
- Augerino
- Aukinko
- Auli
- Auli (Africa)
- Aunyaina
- Ausso One
- Austral walrus
- Australia
- Australian Enigma
- Australian Snubfin Dolphin
- Avagrah
- Averasboro Gallinipper
- Avians
- Awaji Thunderbird
- Axehandle Hound
- Axex
- Ayia Napa sea monster
- Az-I-Wu-Gum-Ki-Mukh-'Ti
- Azerbaijan Baby Bigfoot
- Azhi Dahaka
- Aziza
- Añumin
- Baba Yaga
- Babi Ngepet
- Baby: Secret of the Lost Legend
- Baclou
- Badajoz UFO Creature
- Badalisc
- Baekdu Yacha
- Bagge’s Black Bird
- Bahamut
- Bai-Xiong
- Bai Ze
- Baital
- Bakanga
- Bake-Kujira
- Bakunawa
- Balbal
- Ball-Tailed Cat
- Ban-Manush
- Banaspati
- Bangweulu antelope
- Banshee
- Banyoles Monster
- Baquedano thing
- Bar Juchne
- Baraboo Platypus
- Barbegazi
- Bare-Fronted Hoodwink
- Barghest
- Barguest
- Barloy, JEAN-JACQUES (1939-)
- Barmanu
- Barmouth Monster
- Barnacle Tree
- Barreterito
- Basajaun
- Basan
- Bashkortostan Creature
- Basilisco Chilote
- Basilisk
- Basilosaurus
- Bassigator
- Bat Beast of Kent
- Batsquatch
- Batutut
- Bauk
- Bawokozi
- Bayside Marketplace Aliens
- Beaman
- Beamoc
- Bear Dogs
- Bear King of Marble Falls
- Bear Lake Monster
- Beast Hunter
- Beast Of Avoca Beach
- Beast Of Tenby
- Beast of Bears
- Beast of Beckley
- Beast of Bevendean
- Beast of Bodmin Moor
- Beast of Bolton
- Beast of Boonville
- Beast of Brassknocker Hill
- Beast of Bray Road
- Beast of Buchan
- Beast of Busco
- Beast of Dartmoor
- Beast of Dean
- Beast of Exmoor
- Beast of Gevaudan
- Beast of Gumhill
- Beast of Hrubieszów
- Beast of Karoo
- Beast of Ljig
- Beast of Neamt
- Beast of Purple Trail
- Beast of Tunbridge Wells
- Beast of Wąbrzeźno
- Beast of the Land Between the Lakes
- Beastman of Tonkararin
- Beaver Run Snow Gator
- Beebe's Abyssal Fishes
- Behemoth
- Beithir
- Belarussian Shore Muddler
- Bell Witch
- Belorussian Sky Squid
- Bennu Bird
- Berbalang
- Bergkonge
- Bergman's Bear
- Bermuda Beast
- Bermuda Blob
- Bermuda Tentacles
- Bessie
- Betobeto San
- Bhainsasura
- Bhoot
- Bhootbilli
- BiBi
- Bibliothèque Heuvelmansienne
- Bifang
- Big Bird
- Big Bird!: Modern Sightings of Flying Monsters
- Bigfoot
- Bigfoot/Evidence
- Bigfoot/Expeditions
- Bigfoot/Gallery
- Bigfoot/Sightings
- Bili Ape
- Billdad
- Billiwhack Monster
- Bingfeng
- Bio-Duck
- Biosbardo
- Bird Beast of Var
- Bird of ill omen
- Bissie
- Bitatawa
- Black American Tiger
- Black Bird of Chernobyl
- Black Carpet
- Black Demon
- Black Dog
- Black Dog of West Peak
- Black Eyed Child of Cannock Chase
- Black Eyed Children
- Black Fox of Salmon River
- Black Goat-Man of Wittingau
- Black Sea Giant Snake
- Black Shuck
- Black Stick Men
- Black Swan
- Black Water
- Black dog of Pirque
- Blemmyes
- Bloop
- Blue Crow
- Blue Dilly
- Blue Headed Black Bear
- Blue Mountain Warbler
- Blue Mountains Panther
- Blue Skeleton Man
- Bo
- Boat Hound
- Bobo
- Bogeyman
- Boggy Creek Monster
- Bohun Upas
- Bola negra
- Bondegezou
- Bone Marrow Kiwi
- Boneless
- Bonnacon
- Boobrie