Dimir Keyrune

On command, this keyrune transforms into an
Intellect Devourer that resembles the Dimir guild
symbol, with six bladelike legs. The creature
exists for up to 24 hours. During that time, it
pursues only a single mission you give it - usually
an assignment to take over someone's body, either
to impersonate that person for a brief time or to
extract secrets from their mind. When the mission
is complete, the creature returns to you, reports
its success, and reverts to its keyrune form.