After much deliberation~
Cayci the Galvantula [F]
Ability: Compound Eyes
Cayci start off by laying out Electroweb everywhere to make it harder for Rikki to move, and to determine where the real one is. Then once you've figured that out, use Pin Missle. If he uses Counter, use Struggle Bug instead of Pin Missle. If you haven't figured out which one is the real Rikki by then, use Faint Attack then instead.
Electroweb @ field ~ Pin Missle/Struggle Bug/Faint Attack