Today, we were wishing a Japanese colleague happy birthday in our company group chat while are all working from home. My colleague replies with a message that was just 10 emoji ants. After some back and forth, I learned this was a pun since ありがとう is similar to 蟻が十 (there are 10 ants)
Apparently this is some pretty dated slang, though. But if their testimony is true, it will be pretty impressive if you whip this out in front of a Japanese friend.
Do you guys know of any other common or popular puns?