Fame & Fortune, I thought I'd do another conversion.
Anguyverne Mother & Anguyvernes
't Is a monstrosity, wrote Sir Gwaraine, a monstrosity from the depth of the Lac du Dumbarton. Its wings span twenty feet on each side, more than forty feet in all. Pale and slimy its scales slide along its wings, four score teeth like daggers sharp. A poisonous tail thirty feet long, sting like a thousand bees on a long lance. No knight has defeated the Mother Anguyverne. No knight will, they say, until all her palid spawn are slain as well. For she takes her life's blood and will from them each time she is wounded.
The young wizards apprentice frowned. Then tell me about the spawn, where do they live, what do they eat, where do they breathe? They live in the deep caverns, guarding the treasures of Dumbartons Kings, breathing the silted waters and eating the carrion of the likes of you, young adventurer! Fifteen feet long, slithering like an eel, without wings nor eyes, but with even more teeth than their mother. No knight has survived their bites, even if they are weak. But then, none could breathe water. Only if they would have eaten the gills of the spawn, then they could have for an hour or so. But how to slay them then in the first place? No, 't is of no avail. Sir Gwaraine sunk on his knees and pondered over the still waters of the lake.
OSR: unique creature, HD 9+9, fly 180', swim 120', bite 3d8, tail sting 2d4 + poison
DD2: STR 10, CON 10, scaley hide (armor 4) bite 9 (weapon class 4), tail sting 8 (weapon class 3)
poison in sting (9+ on CON or die, 12+ or S in chest), fly 7, swim 6, INT 0
DD2: STR 5, CON 5, scaley hide (armor 2), bite 8 (weapon class 2), sting 7 (weapon class 1), poison sting 6+ or die, 9+ or S in chest, swim 7, excellent senses 5