These two vastly different species are constantly misnamed for one another and confused by those adventurers who tend to be easily confused. To settle the matter as a record of reference for those who need such things, I offer a brief synopsis on two creatures that would not otherwise appear in any manual on the same page.
Lizard-bulls are scaly reptilian behemoths, shaped rather like bovine, and sporting curved, wicked horns. They prefer fetid swamps. Their flesh is resistant to most weapons, their nostrils steam forth poisonous fumes and their random violent attacks are to be avoided whenever possible. These beasts have been known to devour adventurers whole. Beware as well, their epic screeches!
Bull-lizards are tiny gecko-like reptiles with miniscule horn-like protuberances. These are used mainly during mating season when the otherwise harmless little lizards square off against each other amidst the sands, oblivious to everything around them. Their favored habitat is dry steppe. They feed on thorny shrubbery and avoid all hostile threats by running away as fast as their little legs can carry them. Their powdered little horns sell for good coin among alchemists.
Refer to above whenever unsure of which creature you are facing.