DH has played every course at WDW and doesn't remember that. he remembers the trap at Magnolia, and thinks there's something on Palm, but he thinks it's also a sand trap. Not saying that there isn't, just saying he doesn't remember.
DH is avid Disney golfer and he does not remember a Mickey Head island. There is a Mickey sand trap on the 6th hole at the Magnolia course. The Bonnet Creek golf club has a Mickey practice putting green for Osprey Ridge course. If you go too www.wdwgolf.com click on the Menu (top right corner, on my tablet) and choose a course you can look at maps of each course.