cutting off the tail is hard, i couldn't do it and ended up just killing him.
supposedly after you beat him, there are 2 other places where those guys spawn so you could farm them,
though i haven't found them yet.

they spawn in the garden after you kill manus i read

wait until his diving attack and use a strong physical weapon. all the dlc bosses laugh at elemental/magic damage

well that's not so good for me cause all i really use is a enchanted uchi/quelaag's :S

you can still kill them, i used a +5 lightning washing pole, took me more hits than a strong physical weapon, but hey, just stay alive and it's not so much a problem? haha

well i ment for hitting the tail
not too hard using these weapons imo (hit 55 with enchant uchi, quelaag hits a bit more with 0 humanity)
more so if i spend some time getting humanity to buff up quelaag's

what level are you now? and when do you go on?
i might be able to try to help you, not sure though seeing as i haven't played in a while haha

59 atm
and can't get on atm cause cousin is using tv

i play this on xbox but
that thread died

jus bought the dlc
im about to face the first hydra ofc
should b right near dlc spot ay

you need to get the pendant from the dukes achieve golem before you can do the dlc