Hello fellow investigators!

I recently bought Arkham Horor and have played a few games, so far me and my friends seem to be getting the game and recently had our first victory against Cthulhu himself (lucky enough to have 3 elder signs within the first 2 turns. =P followed by a series of monster surges allowed us to close all the gates), but anyways to the point. Whilst I was in other world I had an encounter in which stated "a slimy monster appears" I randomed a monster from the cup and it turned out to be something wayy out of my league so I thought I would evade it and flee the other world on my next turn.

1). Can you evade monsters in other world?
2). What happens if you leave the world, does the monster just remain on that place hoping for another investigator to come through?
3). What happens if you close the only gate to that world; does the monster return to the cup?

I appologise if these have been answered in a FAQ or something, I've tried searching for the answers except I seem to find 10,000 other posts that mention "otherworld monster movement"

To answer almost all your questions, when an encounter says a monster appears the monster does not remain on the board if it is not defeated, it returns to the cup. If the encounter says a Gate and a monster appear then the monster remains on the board as normal however you will never find a gate opening encounter in another world so a monster will never remain in an other world after combat. And yes you can evade in the other world, if you are successful the monster will return to the cup.

There is one Other World encounter in one of the expansions in which monsters on the gate you came through follow you in and you must fight them, but I think even in that case if you evade them or are defeated by them, they'd return to the gate in Arkham.

I concur with the others. Monsters cannot remain on Other World spaces beyond the encounter that put them there. Win, lose or draw they go back to the cup afterward. There's no movement arrows out there, so moving monsters around in the Other World is undefined anyway.

Steve-O said:

To put it more precisely, Endless, lose, flee, or evade, they return to the cup. Win, you keep as a trophy.

In a similiar vein, we had an investigator that was LiTaS turn into a Deep One due to the mythos card and an unlucky Innsmouth Look draw. That was entertaining.