Tallon Metroids are juvenile Metroids found on Tallon IV. The Space Pirates had transported a number of Metroids they had raised on Zebes to Tallon and were studying their development in different environmental conditions. They look and act exactly like the Metroids encountered on Zebes and SR388, with a transparent green membrane and the ability to latch onto prey as they absorb their energy. Tallon Metroids were also encountered on Aether after the Space Pirates relocated their research there. Their membranes were of a red coloration but they otherwise behaved the same. Like previously encountered Metroids, they were vulnerable to cold-based weaponry.
Tiny newborn Tallon Metroids found in a Space Pirate research facility on Aether. These underdeveloped creatures are not yet able to absorb energy from other creatures and can only defend themselves by ramming enemies. Their attacks are weak and they can be easily killed with any weapon. However, exposure to Phazon radiation will cause the infants to immediately grow into full-sized Tallon Metroids.