So according to the trailor (That is all I wanted to see), the Giant Claw came from a galaxy billions and millions of light years away
https://youtu.be/hOj0nXpRqX8?t=47
As a lowball I will assume the galaxy is 1,000,000,000 light years away
http://www.cultreviews.com/wp-content/uploads/2014/12/giant-claw-poster-3.jpg
It was born on 17,000,000 BC
But it also says it flies at mach 4 speeds, I will assume that is his speed on Earth
The movie took place on 1957 so as a lowball I will assume it took the bird since its birth to get to Earth, or 17,001,957 years.
1,000,000,000 light years/17,001,957 years = 58.8167586c
Earth Speed: Mach 4
Space Speed: 58.8167586c
No matter how you look at it, the bird is FTL, unless the people who made it were idiots (Which they were) so it is more likely PIS