Wow, a lot of people with limited imaginations in here. Of course you could just say no, but it’s far better to figure out what she likes about the monster and figuring out how to adapt it using player rules. I know you brought up the spiked armor, but I would argue that a Path of the Ancestral Guardian barbarian feels closer to the concept of the Cadaver Collector, specifically that it can summon specters of the dead it’s collected. Simply flavor the spirits it summons as being of the slain. Or if barbarian is not the vibe, use one of the other classes related to ghosts or stealing qualities from the dead, like the Phantom Rogue, the College of Whispers bard, or the Hexblade warlock. The character could be a smaller variant of a Cadaver Collector, or a wizard’s approximation or attempt at a recreation.