If it feels hollow and like plastic it is a cast (best way to find out is by checking if it burns with a lighter but that would risk damaging a really nice lookin cast), normally casts don't have such numbers written on them and the colouration also makes it look like a real fossil, but that is just me looking at a photo and when one takes the time, you can perfectly recreate the colouration of a real fossil, I could tell more easily if I was looking at it directly.
Could be a Utahraptor toe claw.
At first I thought Baryonyx thumb claw due to the size but Utahraptor toe claws are roughly that size too.