1. Our dog needs a pet-friendly place to stay.
2. Our dog needs a perfectly friendly place to stay.
3. Our dog needs a friendly-looking place to stay.
4. Our dog needs a large, friendly and comfortable place to stay.
From skimming through grammar websites, I believe the punctuation (including hyphens) above are correct on all accounts. However, I'm confused as to why "friendly-looking" is hyphenated. If the word, "looking" isn't a noun, then wouldn't that make "friendly" an adverb in that case? And since adverbs don't necessitate hyphens (e.g. sentence #2) why does "friendly-looking" get a hyphen? Or does "friendly looking" not get a hyphen?
Thank you for any help on this.