The Onchidiid slug (Onchidiumtyphae) is Mollusca phylum that does not have a shell; they have antioxidant properties and taurine and can function as anticholesterol, antibacterial, and antioxidant. This study aimed to formulate, characterize, and evaluate the antioxidant activity. The formula's optimization is done using the Simplex Lattice Design method. The cream formulation formula was made by comparing the concentrations of triethanolamine and stearic acid, namely Formula 1 (2%:18%), Formula 2 (3.5%:16.5%), Formula 3 (2%:18%), Formula 4 (2.5%:17.5%), Formula 5 (4%:16%), Formula 6 (3%:17%), Formula 7 (3%:17%), and Formula 8 (4%:16%). The cream that had been formed was then tested for physical properties and stability at room temperature on the first day and 28th days