Board Thread:Legitimate Canon Questions/@comment-80.227.35.58-20131230104029/@comment-4091815-20131230155051

The spikes do indeed appear to be made of claws and Gerard's taunting lines - '''::::: GERARD
 * "One of the earliest weapons used by man was the spiked mace. I made one of my own. Loooove to get your opinion on it."

- also suggest he DID make it from claws.

As to which claws, be they from Ennis' betas or some other hapless wolf, and Gerard's motivation in using this particular weapon are matters of pure speculation since it's never explicitly stated in the show.