This looks like a story commanded by Stan Lee. That is, Kirby produced the original story, Lee liked it and told Kirby to bring the character back. But Kirby didn't like the idea so he didn't put much effort into it. Here is my evidence:
- The original story is by Kirby: rich and thought provoking as usual.
- This story also has Kirby touches - like the dramatic and interesting way that Taboo reforms. That has to be by Kirby.
- But bringing him back is a crazy idea, so it must be by Lee (Kirby doesn't do crazy stuff like that): how does somebody survive a hydrogen bomb??? A hydrogen bomb is far more powerful than a regular atom bomb! It wouldn't just separate the mud into small pieces, it would separate every molecule! Kirby would only do this if forced to do so.
- Kirby would not continue this story if he had a choice. Because the story has nowhere to go: this character can survive a hydrogen bomb, and has already shown he cannot be reasoned with. So the only hope is to contact other aliens. But humans have no way to do so: the previous story was about how Taboo has no space ship. So there is nothing for humans to do (other then futile gestures), hence no story. Kirby would not write that unless he had to.
- Yet the ending shows intelligence, so is probably by Kirby: it is the only ending possible, given the constraints. He has to be stopped by his own people in a deus ex machina. And for them to stop him then he must be mentally ill. Lee tends to prefer twist endings and extremes, so a Lee story would have ended with Taboo doing more and more damage until he found some weakness - like drying out of mixing with other mud. That would make less sense but would be more like Lee's other stories.
- The story only has one note, and progresses slowly with lots of repetitive explanation. A sign of Lee.
- But a woman shows initiative and courage. That's a sign of Kirby.
- The early captions have the tell-tale repeated words and verbose redundancy of Lee. But the dialog is better, so is probably more Kirby.
- The moral is good, so that suggests Kirby.
- In general the other stories are by Kirby, then edited by Lee.
And so I conclude that Lee said "I liked Taboo, bring him back", Kirby did not want to, but needed the money so did his job. Lee then added a few more explanatory panels than usual because he liked the character.
A final piece of evidence is that the splash page is merely the cover with minor edits (removing the bus, closing the mouth, etc.). Lee must have disliked Kirby's original splash and so instructed Ayers to modify the cover instead. This is another sign that Kirby plotted the story but Lee took more interest than usual.