According to legend, what creatures were crossbred to create bulettes?
Here's what the lore says, drawn directly from the indexed sources:
Bulette > Bulette > Habitats These creatures were typically found in temperate environments, around hilly landscapes In interior Faerûn, bulettes lived in the Starwood area of the forest of Cormanthor. On the Sword Coast, bulettes were known to hunt in the Lizard Marsh north of Daggerford. and inhabit the mysterious Darkmoon temple along, where they were studied by the ancient elf Alain. Further north, they could be found around the Dessarin Valley. In the Lands of Intrigue, they could be found in the Forest of Tethir and the Calim Desert. In the Moonsea North they could be found in the land…
Source: Bulette
Bullywug > Bullywug > Reproduction Bullywugs were not known to bond in the long-term. Females would lay a clutch of 200 or so eggs once a year, which would be watched over by the collective tribe in a breeding pond. The non-intelligent spawn that hatched resembled large tadpoles and would feed upon insects and small amphibians (including each other) until they were large enough to leave the breeding pool, usually after about six to eight weeks. Following their emergence, the juvenile bullywugs were forced to fend for themselves, with nothing to rely upon but luck and their own strength…
Source: Bullywug
Catoblepas > Catoblepas > Rumors & Legends Catoblepases were popular subjects of stories and legends due to their fearsome and dangerous nature, their silhouettes used in heraldry to symbolize death or doom. It was believed that the first catoblepases were created by a Netherese archmage, though others claimed that these monstrosities were created by gods of rot and pestilence as symbols of their divine influence. Locals considered it to be an ill omen when one of these creatures established a lair nearby, though these claims of misfortune were just superstitions. Other tales said that…
Source: Catoblepas