Translation guide
The plant that cats love, or something irresistible.
The actual plant Nepeta cataria.
Figurative use: something that is extremely attractive to a particular person or group.
Literally 'favorite food', used figuratively for something irresistible.
When talking about the actual plant, use 猫草 or キャットニップ. For the figurative sense, Japanese doesn't have a direct equivalent, so use patterns like 大好物 or 大好き.
Loanword from English, understood by pet owners.
I bought a catnip toy.
New gadgets are like catnip to him.
Simple 'loves' can convey the idea of being drawn to something.
Gossip is like catnip to her.
Proverb meaning 'like catnip to a cat', but uses silver vine (matatabi) instead.
Talking about video games is like catnip to him.