to start:
Alvina's wood: Bp mushroom parent with 2 mushroom children (may be more in the area but these killed be in one hit)
Butterflys forest/ dark root basin: BP stone guardians (6 at once and in ng+ their defense is obscene.)
Tomb of the giants; BP skellie dogs and sword giants, one spot has multiple bp dogs at once, beware.
catacombs: bonewheels skellies, numbers unconfirmed.
painted world of ariamis: Aparently same as the catacombs(needs confirmation)
Undead burg: one bp firebomber, two bp axemen, one bp sword soldier and one bp spear soldier spaced througout the level.)
Undead parish: bp towerknight(greatsword type) and at least one bp balder knight (rapier using kind) if any one knows of others please say
Dukes archive/crystal cave: bp crystal golems in the forested area and in the cave, unknown what appears elsewhere in the level.
these are the only one i know or have heard about, please contribute so that our lord Nitos curse may be spread more efficiently!