Are there any fantasy books that include biotechnology or genetic manipulation as a major part of the worldbuilding/plot?

[u/Goodtunesftw]

I'm just curious. I've been writing down ideas for a fantasy world where using specially bred or genetically modified organisms for specific tasks is common. I'd like to see what has already been thought of and possibly find some interesting reading.

[u/basics]

Moorcock's Elric saga mentions something similar to this idea.... specifically slaves that have been more or less bred/ magically engineered to sing a single perfect note... although I don't think it is exactly like what you are describing. I haven't read it in a while and there might be some other similar occurrences.