In REPO, players encounter various monsters while collecting valuables, each with unique abilities and challenges.Killing monsters in REPO rewards players with orbs worth $1k to $8k, which are also valuable items.Level one monsters like the Peeper and Shadow Child are relatively easy to handle and don't require strength upgrades.Gnomes travel in packs, causing damage to players and loot, but can be picked up and thrown to defeat them.The Apex Predator may seem harmless initially but can transform into a vicious creature causing damage.Spewers can attach to players, causing damage and vomiting, but can be pushed away or smashed to eliminate them.Level two monsters like Rugrat, Animal, and Upscream pose greater threats, requiring strength upgrades or teamwork to defeat.The Chef, Hidden, and Bowtie present unique challenges due to their abilities like invisibility and transformation.Dealing with level three monsters like the Giant Head and Robe demands more strategy and coordination to avoid getting damaged.Trudge, the strongest monster, requires careful planning and execution to defeat due to its various lethal attacks.