I got mine in blood dungeon - nice single spawn that you can work to find strong kits and then recall out and relog to bring them out safely.
They're quite simple to tame, though they will aggro on you and firepuff a little, but no tougher than taming any other pack critters really. It helps if you can clear the surrounding area of any imps that may be lurking around too, then you have space to lead tame without bumping into spawn.
They spawn in a few other spots too,
here's the Hunter's Guide page for them with more info.
Wenchy