In the Kick the Can timeline, Pom Pom's counterpart is Fat Dudley. Whereas Pom Pom has limbs but no extremities (arms and legs but no hands and feet), Fat Dudley has the reverse: hands and feet but no arms or legs. In addition, Fat Dudley actually wears clothes, including a hat, whereas Pom Pom rarely wears clothing.
The most striking difference, however, is in speech patterns. Where Pom Pom only speaks in bubble-blowing sounds, Fat Dudley appears to sing. This doesn't make him any more comprehensible to viewers, however, since he only knows one syllable; the end result sounds like the adults from the Peanuts cartoons.
In the Stinko Man 20X6 timeline, Pom Pom's counterpart is Pan-Pan. Pan-Pan is supposed to be a panda (though he looks more like a black bear wearing briefs), and as such, does not speak at all. Thus far, he has only been sighted bouncing around and eating; evidently Pan-Pan wields a mean set of chopsticks. He seems somewhat clumsier than his counterparts, given his proclivity to fall onto other characters, much to Stinko Man's delight.