螃蟹的英文是 crab。
螃蟹是一种甲壳类动物，属于节肢动物门，腹足纲，又称爬行动物。它们有两对触角，一对外向的大钳，四对足，大多数种类在水中生活。螃蟹是常见的海洋动物，也有一些种类生活在陆地上。
例句：
There are many types of crabs, including hermit crabs, stone crabs, and blue crabs. (有许多种螃蟹，包括海胆螃蟹、石蟹和蓝蟹。)
I love eating crab, especially when it's steamed and served with butter. (我喜欢吃螃蟹，尤其是蒸熟后搭配黄油食用。)
The crab's shell is hard and helps to protect it from predators. (螃蟹的壳很硬，能帮助它抵御天敌。)