Can't seem to get past this one. Is there a specific weapon or spell that works best?
thanks

A vorpal blade, if the poem is any guide :D!

EDIT: On a more serious note, you maybe need to level up your party a bit more and then try again.

if you are refering to the Bard's Tale I, i seem to remember in the originl veersion from back in the day, that there is a crystal or glass sword in a dungeon. I think that may be the needed weapon, but i cant remember for sure.

Actually (speaking of BT1), that weapon is past the Jabberwock, and is needed for a later enemy, not the one guarding it.

Phase Door and Apport Arcane are allowed on this floor, so you don't need to fight this enemy; instead, just PHDO or APAR around it, and you can still get the weapon.

If you wish to fight, try using your Bard to lower your AC, of if breath attacks are an issue, use the luck song (assuming it works in the version you're playing; I believe it doesn't worh in the DOS version). If you're having trouble hitting the enemy, you could try casting Stone Touch; if it works, it's an instant kill.

If you can survive for a while, you could try using Ogre Strength (should boost hit chance), Freeze Foes (might worsen enemy AC), and/or The Seeker's Ballad (supposed to increase hit chance, I believe).