In the darkness, the creature had bat-like ears and moved swiftly through the cave.

bat-like 是由名词 bat（蝙蝠）加上后缀 -like（像……的）构成的形容词，意思是"像蝙蝠一样的"。 like 作为后缀时表示"像……的"，常接在名词后构成形容词，描述某物具有与前面名词相似的特征。