The Unicorn is a helicopter that is named so because of the forward facing cannon above the cockpit. It is a dangerous enemy, with a total of 18 missiles. The only flaw (albeit a large one), is that it can only fire forwards, with the exception of the dual chin gun.
"Silly pilots, skids are for kids!" As a former military helicopter mechanic, I must say that this is an interesting design. It looks like a cross between a utility helicopter and a gunship. I would not want to sit along the outside due to the missile backblast. Marshmellow roasting, anyone?