Umbra, short for Penumbra, also known as the Shadowy Man, is a character who was originally meant to appear in Super Smash Flash 2 as the main antagonist and final boss for Adventure Mode: The Flash Of Shadows. However, after the storyline was remade and the mode itself was scrapped, it was confirmed that they would be no longer be appearing in the game.
The early concept for the game mode stated that Umbra was an entity who possessed the power of the shadows. It had been said that Umbra would make an alliance with other major video game antagonists and villains in the then-planned SSF2 roster, such as Bowser, Mewtwo, Wario, and Shadow the Hedgehog, among other guest characters who were not in the planned roster, possibly including Doctor Eggman and Ganondorf.
From what is known about Umbra's backstory, Umbra originally led half of the Armies of Darkness and was the commander of the CuBots. After being defeated many years ago and appearing in a weakened state, Umbra wishes to take back their power and will stop at nothing to do it. It was never specified what their true powers are, though it was said that they would have three separate forms.
Originally, Umbra was supposed to be a male character. It was suggested, however, to make him female instead. However, no official artwork was made for a female version of Umbra prior to them being scrapped altogether.
Umbra was redesigned by former developer FriendAlias to be included in his "Flash of Shadows" trailer, his proposal for McLeodGaming's April Fools' Day 2020 joke that ultimately released on his own YouTube channel instead. This design for Umbra, along with two designs of a second form, is based on the developers' original concepts for Umbra's female design.