The Coat of Arms of the Isle of Man were granted by Her Majesty by Royal Warrant dated 12th July 1996. The Arms are an augmented version of the traditional arms which comprise the Three Legs conjoined on a red shield surmounted by a Crown and with the motto Quocunque Jeceris Stabit underneath.

In heraldic terms the Arms are described: For the Arms: Gules a Triskele Argent garnished and spurred Or And for the Crest ensigning the Shield of Arms An Imperial Crown proper and for the Supporters Dexter a Peregrine Falcon and sinister a Raven both proper together with this Motto Quocunque Jeceris Stabit.”

The Isle of Man Coat of Arms as displayed in the Royal Chapel at St. Johns...

So why the  Raven ?

In Norse mythology  Two ravens sit on Odin’s shoulders and whisper all the news which they see and hear into his ear; they are called Huginn and Muninn. He sends them out in the morning to fly around the whole world, and by breakfast they are back again. Thus, he finds out many new things and this is why he is called ‘raven-god’  This connects us with our Norse heritage and also reminds us of Odin’s Raven a ship that was built in 1979 for the Millennium and sailed from Norway to the Isle of Man as part of the celebrations.

http://norse-mythology.org/gods-and-creatures/others/hugin-and-munin/

The Peregrene Falcon, well that is another story