The identical twin puppies are two of Spot's puppy amoebas that Plankton trains to distract people for one of his plans. They only appear in "Spot Returns."
The identical twin puppies are tiny translucent green amoebas about the same size as Plankton. They each have an antenna and three dark green spots, along with four legs on each side of their body, and a tail. They each wear a pink pullover with a purple zigzag pattern on it.