The Japanese word for "Aye-Aye" is aiai アイアイ, a katakanization.
Another word for "Aye-Aye" is yubizaru 指猿.
- The old Japanese name for the Aye-Aye, yubizaru 指猿, literally "finger monkey," comes from the fact their middle finger is... weird. It's thin. And honestly creepy. I mean, seriously, it's really, really creepy. If you ever saw it from up close you may nope away faster than you can say "aye, Jesus, that's creepy!"
Scientific name: Daubentonia madagascariensis.
Beware: some kanji that are difficult to handwrite are easy to type on the computer, which may skew the usage statistics.