The first poster covered the definition and three possible interlopers in the story. However, I would argue that Georg and Ulrich are interlopers themselves. Represented in the external conflict of "man vs. nature" found in the story, the two characters may be considered trespassers (interlopers) in the forest. Both attempt to claim ownership, but this something that can only be offered by society.
In truth, the men and their civilization cannot truly claim the land, as evidenced by their inability to tame the natural world. The tree's attack on the men illustrates this idea, and by the end of the story the men are about to be attacked by a pack of wolves. Each man has abused his rights by coming into the forest with the hope of killing his enemy to gain possession of the woods. However, the wolves, beasts that belong to the wild, appear to be the true victors in this conflict, as it is implied they will kill their human enemy and rid their world of these human intruders.
There are at least two types of interlopers in the short story, "The Interlopers," by Saki (H. H. Munro), but only one of the group is deadly. When lifelong enemies Georg and Ulrich finally decide to end their feud once and for all, fate gets in their way. Meeting in the forest one night, they both plan to kill one another with their rifles, but neither can pull the trigger. Suddenly, a tree is felled by a bolt of lightning, and both men are pinned helplessy beneath it. Each of them expect to be found by their friends, who will then leave the remaining man to die alone. But before this happens, the two men make nice and decide to end their quarrel for good. Joining forces, they both call out for help. When they see movement in the darkness, they think they are saved. But, no! They are not men, they are hungry wolves instead. The reader is left to guess what happens next.
The interlopers, or intruders, are the wolves. If the expected arrival of the other men had occurred first, they, too, could have been considered interlopers upon the two men's quarrel. And, the tree which fell on them could also be looked upon as an unwanted interloper as well.
The interlopers in the story are two men, Ulrich von Gradwitz and George Znaeym. The two are involved in a feud that has spanned three generations, all resulting from a lawsuit Gradwitz' family placed against Znaeym for the land. The courts granted them the land, however the Gradwitz' family refused to give it up. The two families have been involved in a feud ever since. The term "interloper" refers to a person who interferes in the business of others. The two are considered to be interlopers by the other as they both believe the other is trespassing on his land.
However, the wolves at the end of the story are also technically interlopers since they are intruding on the two men caught under the tree. Though in yet another view, one could say the two men are interlopers in the woods which are really owned by its animal inhabitants, namely the wolves.
in simple plain english the interlopers are the wolves the tree and the 2 men