Monster legends should make a monster trade island, so people can trade monsters for gold, gems, food and other monsters. You should be able to set the monsters item to trade for. Please do it.

@Ish-Man This has been requested several times at least. I think it is save to say that it will not happen. You have cell trading once you get the Lab and that will probably be your only option. It is not a bad method of getting or improving monsters.