Dupli-Arms grants Mezo arm-attached tentacles that can replicate parts of his body.
Mezo is able to reproduce any of his body parts, including ears, eyes, mouths, hands and so on, with said parts taking form through pods located at the tip of each of his tentacles.
The duplicated parts are actually enhanced versions of the original ones, granting Mezo improved strength and senses. Different parts can be manifested at once too, allowing Mezo to combine his augmented sensory abilities.
The tentacles, just like any part of Mezo's body, are vulnerable to injuries coming from enemy attacks. The same goes for the replicated body parts.
Dupli-Arms makes Mezo excellent for spying and stake out missions, as his tentacle-created parts have heightened functions. As examples, with his eye replicas, Mezo has full peripheral vision, being able to see anything within a 360º field of view, and with his ear duplicates, he can detect sounds from sources behind walls or far away from his position. Mezo also prefers to communicate with others through reproductions of his mouth due to the fact that he's always wearing a mask that covers his lower face.
For combat, Mezo multiplies his already great physical strength by replicating his arms, giving him force equivalent to around half a ton with just one set of his tentacle arms. Mezo is strong enough to carry more than one person on his back with little trouble, and he is further capable of shielding or hiding them from danger thanks to his Dupli-Arms being webbed. This also means that the tentacles can function like improvised wings, letting Mezo glide for a limited amount of time.
It's worth noting that the tentacle pods can recreate even themselves as well, meaning that Mezo can continuously extend his tentacles by just making his pods self-replicate over and over. Additionally, one pod can reproduce multiple separate organs, but doing so makes the duplicates less efficient.