Ztarman3 is a doppelganger of Starman3.
Ztarman3 in Blooper 40, fighting Starman3
History
He first appeared in Blooper 40, as he wanted to take over Blooper Land and wanted to kill Youtube Rangers once and for all. Starman3 and Ztarman3 fought to the death over this, and Starman3 defeated him.
He also appeared in Time 3 (by MarioMario54321) as a helper of Ztarragus, and blocks Starman3 from getting the Star which makes Starragus complete his form. Starman3 defeated him and obtained this Star.
He also appeared in Super Mario 64 Dimensional Heros 5 as he took Mario and Luigi away.
Counterparts and Other Relevant Characters
Fourth Dimensional counterpart: Starman4
Star World counterpart: StarWorldMan3
Mushroom Kingdom/Blooper Land counterpart: Starman3
Crown Dimension counterpart: Starman5