Necrosprites are a mutation of parasprites that has been formed due to the corrupting presence of the Black Book in the Ministry of Image Canterlot Hub. They are similar in appearance to a typical parasprite, but appear to be more like ghostly shadows. Necrosprites move in swarms resembling black clouds with inky tendrils and are completely unphased by any non-magical materials, allowing them to pass through solid objects as if they weren't even there. The buzzing of a necrosprite swarm creates an unhallowed humming noise, and light seems to flicker or grow weaker in their presence.
It is suggested, but never proven, that they feed on the souls of ponies that wander into the MoI building, as warned by the message "THEY EAT YOUR SOUL" painted across a broken terminal in the MoI building's Media Oversight floor. Fortunately, whatever magic keeps most of the Pink Cloud out of the ministry buildings also seems to keep the necrosprites in.