slug

我在菜叶上发现了一只鼻涕虫。

I found a ___slug on the lettuce leaf.

警方在犯罪现场发现了一个弹头。

The police found a ___slug at the crime scene.

别像个懒虫一样躺在沙发上了，快起来帮忙打扫！

Stop being such a ___slug on the couch and come help with the cleaning!