Shikigami are paper charms, or golems, enchanted by the user to take the physical form of an animal to act as a familiar.
While quit adept at mimicking a variety of forms, depending on the power of the enchanter and its master, a shikigami does not possess much in the way of attack power and so these charms are mainly used for surveillance or as extensions of the spell caster to assist as guides or overseers. If a Shikigami is "killed" or it loses power, it is returned to it's paper form unless heavily shielded with protection spells.
Historically, users of Shikigami were practitioners in Onmyodo, a Traditional Japanese art of cosmology. In Negima, it appears to be a common practice of western (meaning the Kansai, not European.) magic. These charms can share a telepathic bond with their user, allowing the spell caster to have an extra set of eyes or, as seen in the Mahora Martial Arts Festival, act as guides for another person, as Setsuna uses her paper "demon" familiar to guide Takahata through the maze of sewers under Mahora. However, in this instance, the golem is acting alone, as stated by the charm itself. In this case, it seems charms can gain a measure of intelligence of their own and retain information to be relayed to their tied spell caster later.
The only way so far shown that these charms can be used in battle is displayed by Kotaou Inugami when he summons a spider demon using a charm spell and heavily shields it to protect it from harm, allowing it to be used as a weapon due to the fact it's paper consistency is protected. Asuna however, cancels this tactic out with her magic cancel ability, leading to quesiton how effective this technique is in battle.
- Motoko Aoyama's pet crane, Shippu, which was given to her by her sister, Tsuruko Aoyama, is actually a Shikigami whose size changes depending on its master's power.
- Some examples of such charms are Kotarou's spider demon, summoned to fight Negi and Asuna in the thousand gates, and Setsuna Sakurazaki's miniature spirit form. Negi himself also uses this magic to create a miniature form of himself, which is then expanded into a life sized form by Setsuna.