So I'm A Spider, So What?, Vol. 1 by Okina Baba

After a classroom is mysteriously reborn into a fantasy world, one girl wakes up as a lowly spider monster trapped in a deadly dungeon and must rely on cunning, instincts, and the bizarre game-like mechanics of her new reality to survive. Struggling against stronger predators, scarce resources, and the constant threat of death, she learns to craft strategies, evolve her abilities, and adapt her human memories to her fragile arachnid body. The narrative blends dark humor, intense survival challenges, and world-building as she uncovers hints of the larger mysteries behind the reincarnation and the strange rules governing their fates.

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