Tensei shitara Slime Datta Ken, Kumo desu ga, Nani ka? Recommendations
Two Isekai novels where the MC reincarnates into an RPG-like Fantasy world, as 1 of the weakest monster; with skills, levels & evolution trees. Both worlds have multiple other Japanese citizens who have also reincarnated into the world and the novels have snappy comedy. Main difference being...
Reincarnated as a Slime ... More Kingdom Building, with a large community feel.
So I'm a Spider ... A lot more Action Adventure oriented, with the MC going solo most of time.
World build and character models are pretty much the same. Both also narrate from different POV's other than the mc's