how to make those wandering marines on map99?

[odysseyofnoises]

in The Stronghold MAP99 there is this yellow-green colored marine that just wanders around really slowly, and thats pretty cool, how to make that in my wad?

[odysseyofnoises]

actually i figured out how to do it xD but another question: does anybody know how to make it so that when you jump into a deep water sector it kills the player??