If you are careful, I believe it is possible to get to Nexus from the Froglok starting area, if you can make it to the Blight (The Grey). It might be hard not to suffocate and make it to the Barrens zone (Marus Seru), but from there you can make it to the Nexus. You should be able to avoid all monsters. Mistwoods or Great Divide both work as newbie zones.