Over the years there were rumors about the mysterious red eyes behind Snively in the elevator belong to Metal Sonic or Knuckles but this was proved false after the show's writer, Ben Hurst, revealed it was Naugus.
Sally reveals that the Southern & Eastern Freedom Fighter's leader's names are Pollo and Dirk.
In this episode, it wasn't clear which is Pollo and which is Dirk. However, according to "The Doomsday Project" storyboard/outline on Shout Factory's DVD: Pollo is the rhino and Dirk is the bear.
The red eyes at the end of this episode belong to Naugus from "The Void". Making this Naugus's unofficial second appearance in the series.
Lupe appears in this episode but does not speak.