Size

Size is the term used to dictate how big or small a monster is. The new size scale was first incorporated into Monster Hunter Freedom, where, in the hunter's card shows only the largest size of all the monsters they defeated. In subsequent games monsters of the greatest and smallest size recieve a gold crown, placed next to the name of the monster in the hunter's card. In MHF1, as well as all following games, fairly large monsters will receive silver crowns.

Subspecies are not included in this list. This however, changes in Monster Hunter Portable 3rd, where each subspecies has their own list.

Some monsters vary in size from quest to quest. This list goes according to the sizes most frequently observed.

Tiny Monsters
Monsters smaller than humans.
 * Smaller Fish, like Tuna.
 * Felyne and Melynx
 * Shakalaka (like Cha-Cha and Kayamba)
 * Vespoid and Bnahabra
 * Hornetaur
 * Altaroth
 * Giggi
 * Kelbi
 * Mosswine
 * Kunchuu

Small Monsters
Monsters equivalent to, or slightly larger than humans.
 * Some of the larger Fish. Sharqs, Molids, etc...
 * Anteka
 * Bullfango
 * Rhenoplos
 * Epioth
 * Remobra
 * Conga and Blango
 * Hermitaur and Ceanataur
 * Velociprey, Genprey, Ioprey, and Giaprey
 * Velocidrome, Gendrome, Iodrome, and Giadrome
 * Jaggi, Jaggia, Baggi and Wroggi
 * Cephalos
 * Delex
 * Uroktor
 * Ludroth
 * King Shakalaka
 * Kirin
 * Slagtoth
 * Gargwa
 * Sukuagiru
 * Pokara

Medium Monsters
Monsters about the size of a Tank.
 * Abiorugu and Giaorugu
 * Hyujikiki
 * Brachydios
 * Arzuros
 * Popo
 * Bulldrome
 * Congalala and Blangonga
 * Rajang
 * Aptonoth and Apceros
 * Yian Kut-Ku and Yian Garuga
 * Hypnocatrice, Breeding Season Hypnocatrice, and Hypnocatrice Rare Species
 * Volvidon
 * Great Jaggi, Great Baggi and Great Wroggi
 * Gypceros
 * Qurupeco, and Crimson Qurupeco
 * Daimyo Hermitaur and Shogun Ceanataur
 * Cephadrome
 * Gobul
 * Nibelsnarf
 * Royal Ludroth and Purple Ludroth
 * Barroth and Jade Barroth
 * Gigginox and Baleful Gigginox
 * Tigrex, and Tigrex Subspecies
 * Nargacuga, Green Nargacuga, and Lucent Nargacuga
 * Barioth and Sand Barioth
 * Rathalos and Rathian
 * Basarios
 * Kushala Daora
 * Teostra and Lunastra
 * Chameleos
 * Zinogre and Stygian Zinogre
 * Espinas, Espinas Subspecies, and Espinas Rare Species
 * Pariapuria
 * Dhuragaua
 * Berukyurosu
 * Doragyurosu
 * Akura Vashimu
 * Akura Jebia
 * Kamu Orugaron, Nono Orugaron, and Midogaron
 * Gurenzeburu
 * Khezu
 * Tetsukabura
 * Goa Magara
 * Loro Gougarufu and Ray Gougarufu
 * Anorupathisu
 * Pokaradon
 * Nerusukyura
 * Kechawacha
 * Aruserutasu
 * Lagombi

Large Monsters
Monsters exceeding the size of small houses.
 * Plesioth and Lavasioth
 * Goruganosu and Aruganosu
 * Lagiacrus, Ivory Lagiacrus, and Abyssal Lagiacrus
 * Agnaktor and Glacial Agnaktor
 * Monoblos and Diablos (and their White/Black subspecies)
 * Gravios and Black Gravios
 * Uragaan and Steel Uragaan
 * Deviljho and Savage Deviljho
 * Duramboros and Rust Duramboros
 * Akantor, Ukanlos, and Odibatorasu
 * Fatalis, Crimson Fatalis, and White Fatalis.
 * Alatreon
 * Yama Tsukami
 * Shen Gaoren (Crouching)
 * Amatsumagatsuchi
 * Shanthien
 * Zaboazagiru
 * Kuarusepusu
 * Garara Ajara
 * Generu Serutasu

Gigantic Monsters
Monsters large enough to occupy a football field.
 * Shen Gaoren (Standing Up. Very long legs.)
 * Lao Shan-Lung
 * Jhen Mohran and Hallowed Jhen Mohran
 * Ceadeus and Goldbeard Ceadeus
 * Dire Miralis

Colossal Monsters
Raviente and its subspecies are currently the largest monsters in the Monster Hunter universe, easily the size of a small island. So large that they do, in fact, get their own category.

Specific Crowns
These are the particular sizes of some monsters when they hit a certain crown limit.

Trivia

 * It is interesting to note that monsters appear considerably larger in Monster Hunter Frontier than in any other game.
 * Some quests require to hunt unusually small versions of medium and large monsters, such as the Yian Kut-Ku, Khezu, Uragaan or Qurupeco.