Cyclades
What happens if Polyphemus is placed on an island that already holds a Minotaur, Chiron or Medusa?
One forum reply gives this answer, and no official ruling confirms it.
- FabienC · Community · 2011-05-29
Both figures are discarded immediately, so Polyphemus does not stay on the island. The source does not say whether he pushes fleets before leaving.