A magus' servant. Depending on the school of magecraft, they were called things like
Familiars or Agathions, or as in the Far East, Shikigami. Touko was of course using a
puppet. Having taken an interest in the rumors of a certain magus using wires to create
Familiars in the Fourth Holy Grail War, she had made a puppet out of springs, gears,
and string herself.