Kevin knows German, as Noah says that Kevin translated Karl's dialogue in "My Grandfather Karl". Kevin has only been mentioned by Noah when talking about Victor Park; Noah says that Kevin is the only person he would trust to go into Victor Park with him. Because Karl's journal is written in German, Noah has said that he would get Kevin to help translate it, whenever he obtains it.
Around December 2011, after Noah was returned after his repossession by the Observer, Noah saw Kevin for the first time since he had asked him for help in translating Karl's German. According to Noah's Formspring, Noah noticed that Kevin had grown his hair out and began wearing glasses instead of contact lenses. Noah spoke with Kevin, who asked Noah about what some cryptic messages that he found might mean. Noah also remembers Kevin asking him about "note cards" and "compensation", and noted that he was nervous sounding.
A justified speculation often made by TribeTwelve followers from these clues is that Kevin may in fact be the Observer's "vessel".
Kevin made his first appearance on the November 11th video showing the cards "compensate", "Inevitable" and "Kevin" to the camera. The handwriting was much like the Observer's handwriting. To further back up the theory that Kevin is The Observer's vessel, the note cards read "One Of Us" with The Rune Of Severance at the very last second they are shown.
On November 10, 2012, Noah tweeted pictures of a letter he had received from the Observer that day. The letter contained writing that said "I'm so sorry Noah, They're too powerful, Kill me I'm only a tool, He can't use my body then, Kill me, Kill me, Kill me". Noah had claimed this was the handwriting of Kevin.
Kevin as The ObserverEdit
After the video The Live Stream Incident, Kevin was confirmed as the observer's vessel.
There has also been a possible form of evidence to this in Box Analysis, when Noah found footage on the phone. It is actually very possible that the phone belonged to Kevin, which can be partly confirmed when a close up of his eye was seen at the very end of the video that was on the phone, yet any further proof did not appear in that video.
There was proof however, in November 11th, when Kevin was seen for the very first time in the series when something went wrong with Noah's camera. Yet while it seemed that he was speaking, there was no audio; instead he held up several note cards, one of which presented his name. He was also seen after the Slender Man dragged Noah away, appearing under the bed smiling with the words 'GOT YOU' nearby. The next footage of Noah being 'taken' showed the Observer with Kevin's face, smiling throughout most of the video. This was the first time in the series when the Observer was seen using Kevin's body.
In The Live Stream Incident, Noah said that the handwriting in the envelope that he received was Kevin's handwriting, confirming Kevin to be the Observer's vessel.