The answer is narcotic. It is any of a class of substances that limit the faculties, as opium, morphine, belladonna, and liquor, that in expansive amounts deliver elation, trance, or trance state, that when utilized continually can bring about habituation or enslavement, and that are utilized as a part of medication to alleviate torment, cause sedation, and instigate rest.
Toys are meant to be used for the child's imagination. If the child feels forced into using something in only one particular way, this can trigger a breakdown.