I remember the Owlbear/Gryphon was was from a D&D art book for kids, never seen more of that though
If you like these pictures, the books are “Baby Bestiary I + II”.
Yeah, I have the D&D book for kids; my son is learning soon. 
That was a reference to me getting my butt owned by Callagadra on a beastcaller + HotM build.
FG is not kind to pets that are not Familiars.
Oh yeah I remember the names. Just never found scans or seen them in book stores over here in Hungary.
I only beat it once so far on Veteran with my (to be) Markovian Commando, and never even came close to dying once. Then again this is just Veteran and the character is very heavily defense based. I wanted to make a character that can facetank those bosses that give most of my other builds trouble.
There is a quest where he will make Aetherial Mutagen for you (you get it after reaching Malmouth I think). Usually this just results in XP and Mutagen, but on Ultimate, you get a purple Aether crystal (looks the same as the Aether Shard), double click it and it is a floating little crystal pet that does have an annoying aether hum sound though.
Found it again on Normal-Veteran with another character - this time it was in the Temple of Ateph, in an urn. So I am guessing it is in one of the tombs/temples but it is random which one.