The Silver-Crowned Bats of Turmoil

I've had some fictional ideas swirling around my brain for a D&D campaign. One of these ideas is a giant bat. I got the idea from re-reading the Leviathan Trilogy and seeing the Fléchette bats. I researched a little bit, and I took inspiration from the Golden-crowned Flying Fox, one of the largest bats in the world. In real life, this bat lives only in the Philippine islands. It is unfortunately endangered. In most of my creations, it has something to do with fictional machinery or fictional animal mutations. This one has more mutations applied to a normal bat. In honor of the endangered Flying Foxes, I have named this new species of bat, "The Silver-Crowned Bats of Turmoil"

This bat has a 5.5 ft wingspan, is 1.8 ft long, and weighs up to 3 lbs. Living only upon the peninsula of Turmoil, they live in large packs of 5,000 or more, in humongous caves with large iron deposits. They are omnivorous and can eat small mammals like squirrels and rabbits, as well as berries. When they sense a foreign presence on their island, they send their strongest men and women to take large iron spikes to shoot at the enemy. Where do they get the spikes you ask? Well, they are able to eat the iron deposits and change them into large iron bars within their stomachs.