As one of the founders of Silver Gryphon Games I have a fondness for gryphons. It seems only natural, then, that I write up a few variations of the standard gryphon (or griffon, griffin, or gryfon, as you like) for OSR uses.
Gryphon
Common
Armor Class: 5 Hit Dice: 7 Move: Normal move: 90' (30'); flying: 240' (80') Attacks: 2 claws/1 bite Damage: 1-8/1-8/2-12 No. Appearing: 1 (1-2) Save As: Fighter: 3 Morale: 9 Treasure Type: V Alignment: Neutral
Gryfalcon
Armor Class: 5 Hit Dice: 6 Move: Normal move: 90' (30'); flying: 280' (100') Attacks: 2 claws/1 bite Damage: 1-6/1-6/2-8 No. Appearing: 1 (1-2) Save As: Fighter: 3 Morale: 9 Treasure Type: U Alignment: Neutral
Opinicus
Armor Class: 5 Hit Dice: 7 Move: Normal move: 120' (40'); flying: 240' (80') Attacks: 2 claws/1 bite Damage: 1-8/1-8/2-12 No. Appearing: 1 (1-2) Save As: Fighter: 3 Morale: 9 Treasure Type: V Alignment: Neutral
Demigryph
Armor Class: 5 Hit Dice: 7 Move: 120' (40') Attacks: 2 claws/1 bite Damage: 1-6/1-6/1-10 No. Appearing: 1 (1-2) Save As: Fighter: 3 Morale: 9 Treasure Type: U Alignment: Neutral
Hippogriff
Armor Class: 5 Hit Dice: 7 Move: Normal move: 90' (30'); flying: 240' (80') Attacks: 2 claws/1 bite Damage: 1-8/1-8/2-12 No. Appearing: 1 (1-2) Save As: Fighter: 3 Morale: 9 Treasure Type: U Alignment: Neutral
Gryphons are powerful predators, but generally avoid fights unless very hungry. They are found in all manner of climates, but tend to prefer mountainous areas. All variations of gryphon except the demigryph will build their nests (called aeries) in high-up places that are easily defended and difficult for non-flyers to reach. Gryphons are social, intelligent creatures and will sometimes be found in small communities of gryphons. They mate for life, and if their mate dies, they will rarely take another mate, instead living the rest of their life alone. Some cultures use gryphons as fighting-beasts or as mounts. Because they are intelligent creatures, gryphons in this capacity are usually willing participants in this arrangement, but not always. A person having a gryphon as a mount will usually have a strong bond with that creature, and vice versa.
Common: The common variety have the body, tail and back legs of a lion, and the head, wings, breast, and front legs of an eagle. They stand roughly 6-7' high at the shoulder, making them a little larger than most horses.
Gryfalcon: Gryfalcons are very similar to common gryphons, but instead of bearing the likeness of an eagle, resemble a falcon. They are typically smaller and more lithe than their common kin.
Opinicus: The opinicus has the full lower body of a lion, including the front legs, and the head and wings of an eagle. Unlike common gryphons, they do not have tufted ears. Opinici tend to be slightly more aggressive than other gryphons.
Demigryph: A demigryph (or keythong) looks very similar to a common gryphon, but has no wings. Demigryphs are fonder of plains and hills than their kin, and are more likely to interact with humans and other sentient species.
Hippogriff: Hippogriffs have the body, back legs, and tail of a horse instead of a lion. They are otherwise similar to common gryphons. These creatures are rarely seen outside of forested mountains.