Vegan+Unarmed Monk approaching Sokoban ZOO [3.7.0]

I am just steps from entering zoo level. My pet was morphed into Ettin Mummy, which helped me tons with nasties on the 3rd level. PC is lvl 7, have no healing spells found so far, just confuse monsters & poly. AC =1, magic whistle. No key, so my stealth is kinda useless i guess.

My idea is go down to the town, find a key on any GM level or, if needed, on watchman's body. Should I worry less and hit zoo loud and hard on the ettin's back?

Another question is, when to think about morphing this pet into other crit...like, I know the effect is random, but how long this EM will be helpful?