MakeHuman

MakeHuman is a free and open-source tool for generating humanoid characters with detailed adjustments of proportions and other body/facial features.

"Project Maiko" (!) by Colin Barton is a good example of how MakeHuman can be used to generate a medium-poly character well-suited for renders or in-game use. The full list of updates/tutorials under the Maiko project is HERE.

An alternative to MakeHuman was MB-Lab, a fork of the discontinued Manuel Bastioni Lab (developed by a former user of MakeHuman). Unlike MakeHuman, MBL existed only as a Blender plugin. It featured new base mesh topologies, as well as a muscle rig for more advanced deformations. Facial animation and "proxies" (alternative topologies) were in development, but the project was discontinued in July 2024 (former web page, archived GitHub repo).

Another good alternative is Fuse.