The sea otter floats on its back on the water, smashing open shells with a stone.
Tips
memory
海 (sea) + 獭 (otter) - exactly 'sea otter'. The character 獭 has the dog/animal radical 犭 on the left, marking it as an animal. Compare 水獭 (river otter, freshwater otter).
culture
Sea otters are widely loved in Chinese-language internet culture for their habit of holding hands while sleeping so they don't drift apart - videos of this behavior regularly go viral on Weibo and Douyin tagged 海獭手牵手.