E-121 Phi (Ｅ-１２１ ファイ E-121 Fai?), technically referred to as E-121 “Φ”, is the collective name for several robots built by Dr. Eggman based on Emerl. Dr. Eggman took the Gizoid's data and copied it to create the Phis. They are massed produced, though only fourteen are seen. The Phi robots are powered by Chaos Emerald Shards, rather than whole Chaos Emeralds.