During the prologue you will unlock the character Jophery Brown, who has a taser pole as his weapon. As you continue the story shortly later, you will unlock the character of Timmy. Simply have your second character set as Timmy and press
with Jophery Brown to hit Timmy and bam ... Achievement Unlocked.
Hint: You can change characters in the hub by holding
and moving
down to select any unlocked character.