Just a funny way to write "Koala"
The really funny thing about the tattoo is not that it says "Koala", but that one kanji is turned the correct direction and the other two are upside down. The person who did this tattoo hadn't the first clue about kanji.
Now you can start calling your friend "Koala" if you need a good nickname for him.
Tell him the time to verify kanji tattoos is BEFORE having them done.