The only Pokemon on mirage island is wynaut
A mirage is caused by cold air passing through warm dense air. The light is then bent and reflects into a mirage.
Rarely Mirage Island will appear on the Route east of Pacifidlog Town.
The Mirage Island in the older Generation III games has a very slim of appearing. The Mirage Island randomly generates a number and if it matches the ID of one of your Pokemon, it will appear and accessible for 24 hours. An elderly man facing towards the window in Pacifidlog Town will let you know when Mirage Island appear.
A Wynut, although you have to be VERY lucky for mirage island to appear and Wynut is the pre evolution of Wobbufet
In Pokémon Emerald, Mirage Tower will appear in the Desert that is to the North of Mauville City however it will only appear once you have spoken to the Ruin Maniac in Fallarbor Town. Once you head into the Mirage Tower, you will need to use the Bike that is the Mach Spike because of the various sensitive cracks in the floors. However once you have picked 1 of the Fossils then it (the Mirage Tower) will disappear and it will not return at all.
It will disappear and reappear in the desert on Route 111 as the player visits and leaves the Route.Do not confuse it with Mirage Island.
To get a Wynaut, A lady will give you an egg in Lavaridge town. It will eventuall hatch into Wynaut. Or, Infinite Wynaut will appear on Mirage Island. But seeing Mirage Island is as hard as winning the lottery! A number will be picked every day. If that number matche you pokemon's ID number, Mirage Island will appear.
wait for the old guy in the house in southeast Pacifidlog Town to say OMG i see Mirage Island Then you use SURF and go east from Pacifidlog till you reach Mirage Island
Mirage Island appears when you have got a Wanuat. Sometimes Mirage Island appears and sometimes it doesn't - the old man will normally say " I can't see Mirage Island today" but rarely he will say he can - and that's when it appears. DO NOT let your Wanuat evolve otherwise you will not find Mirage Island.
lifters
Well when you acquire one of the fossils in the desert the other fossil you didn't choose will appear in mirage tower so it can be either the root fossil or claw fossil.