Material Studies: Clay is a research option found under the Golemancy tab that can be purchased with 3 levels of experience after researching Material Studies: Iron, and allows for Clay Golem bodies to be produced.
Hardened Clay is easy to find or create, especially in mesa biomes or if one has access to Alchemical Manufacture. Although not as quick as other early Golems, it has decent health, is very cheap and is immune to fire damage, making it a good choice for Golems at work in the Nether or that may be working in environments where fire damage may be a common danger.
Clay Golem Body
Materials Needed: 3 Hardened Clay