This stick is fairly plain in it's appearance apart from a singular strange rune carved into one end.

The stick can be thrown using a bonus action

When thrown, this stick flies in a straight line with a distance equal to your familiar's speed and any familiar who appears as a dog, wolf , or similar animal immediately takes chase.  While chasing the stick, the familiar gains +10 to it's AC and ignores difficult terrain but can take no actions apart from dashing after the thrown stick.  Any creature within one size class of the familiar who is in the path of the familiar is knocked prone and must make a DC 10 Dexterity save or takes 1d4 points of bludgeoning damage.  

Once the familiar had reached half it's movement speed, it catches the boomerang and returns the stick to it's owner.  If the stick flies somewhere the familiar is unable to reach, the familiar moves as close as it can, and waits for the stick to begin returning.  If the familiar is killed during the chase,  the stick returns to the thrower but any enemy who the familiar did not reach remains standing.

"This stick was made to commemorate the legendary corgi familiar, Brucewillis"

Notes: humanoid who has a familiar, Debuff, Utility, Combat