I like the irony of reverse psychology being used to contain an entity that can make people say the opposite of what they intend.
However, I feel that both the tale and the SCP itself are a bit lacking in the usual science-y flavor of SCP content. While there's a fantasy element to most if not all SCPs, there's generally some kind of explanation or suggestion of how and why they have anomalous properties beyond "they just do." The rules of the universe are pretty nebulous around here, but I don't know if 'low power fish gods' really fit in, at least not without a better explanation. Slap some pseudoscience on there, at least enough to justify the crab speaking English and fish being able to pray, and it'll be a major improvement.
I'm not sure how I feel about the concept of praying fish overall. Maybe a specific population of anomalous ocean critters that can pray would be better than just implying that all marine life except krill is sentient enough to pray?
Also consider explicitly stating that Otolop is changing forms, and maybe describe what it looks like (is it instant, is there a flash of light, can you see it happening?) instead of abruptly mentioning what new form he's in. Jumping from form to form so suddenly is needlessly jarring.
The phrase "Escape can wait, if it means these fuckers get to relax" is also a little confusing. I'm assuming it means that escape would result in the robotic attendants being able to relax and the crab doesn't want that, but it reads at first glance as if waiting to escape would allow the attendants to relax.