"Mischief" (aka "Pink Guy")
"Mischief" as commonly referred to by fans, (The Character remains as yet officially unnamed) is a re-occurring character in the Interface series and is a key player in the plot.
Origin
"Mischief" is believed to originally have been an American Human within the US Navy although his being was altered by his involvement in the 1943 Philadelphia Experiment. The Experiment has been subject to much speculation and conspiracy however within the Interface universe the Ship was teleported from Philadelphia to New York, the crew fusing to the hull during this process. "Mischief's" previous being was destroyed and he became the creature he appears as in the series.
Physicality
Although "Mischief" appears mainly as a pink 'Worm-Like' creature, they are known to take many other forms such as a Bus or a Sunflower. It is believed that this shapeshifting power may have been gained through Cerebral Electricity a mysterious energy which appears throughout the Interface series which has been show to be used by Kami and speculated (although not explicitly seen) to been used by The Ghost. It is unclear the full extent of the power gained by "Mischief" through use of Cerebral Energy.
"Mischief" taking form of a Bus (Ep 02 of Interface)