Rift Creatures mimic the Monster of the Month (MOTM) monster groups. When a rift is spawned, the rift will generate a random group of MOTM. All creatures that spawn within a rift will be Paragon. This means they will be much harder to kill then normal. Also, sometimes included in the rift is a Treasure Goblin that has an improved loot table. In addition to armor, weapons, and gold, Treasure Goblins will drop miscellaneous seeds and Hybrid coins. If you think you are hearing a mongbat, prepare yourself!