The ferocious-looking lion made all the tourists stop in their tracks.

ferocious-looking 是由形容词 ferocious（凶猛的、残暴的）和现在分词 looking（看起来）组成的复合形容词。ferocious 来自拉丁语 ferox（凶猛），-looking 表示"看起来...的样子"。整个词描述"外表看起来很凶猛"的意思。