This HM is on the Hidden Mickey Jungle Trek at the AK! (Technically, it's called the Maharajah Jungle Trek, but there are so many HM's in there that I have re-named it!) It is just past the Tiger Exhibit in the Elk's (?) deer exhibit - along the wall closest to the Tigers. Really hard to see and very small - I knew exactly where it was supposed to be or I never would have seen it!
Here's another from the HM Trek: