Thanks lorimmel for telling, how to find the quest.
And thanks idril for the link to the hatchery, now my pets are growing. I searched google for that, cause this worked well for dragencave - there are quite many hatcheries for dragons (thanks blobber and Dracaena for their pm a few weeks ago - that helpt very much). But I couldn't find some for magistream (maybe one, but that didn't work).
Now I solved the quest and got a hellhound. And then I got a pm if I want to trade it. Probabely I give it away, because I'm not really activ at magistream.
But since I don't know at all, what I'm doing there at magistrean, I just want to ask: Is it something special? A little bit more worth than all the other createres from the stream? Is it much more worth? Maybe I'll never get one again?