// source http://jsbin.com/besaziwibe

jsbin.besaziwibe.js

var o = {};

var animals = ["cat", "dog", "fan"];

for(var i=0; i < 3; i++){
  var animalName = animals[i];
  var funName = animalName + "Fun";
  o[funName] = function(){
    return animalName;
  };
}

console.log(o);
console.log(o.dogFun());
console.log(o.catFun());
console.log(o.fanFun());