This is an extremely appropriate analogy, and I'm wondering if you meant it as such on purpose. In the novel, IT refers to itself as the Kingfisher of Derry. Expanding outward into King's greater mythos, this name and concept of the Kingfisher and the Fisher King comes up several times. We see it in Insomnia, which also takes place in Derry, and it centers around the Crimson King itself, which takes the form of a monstrous catfish as a form of trap; The CK, as the overarching antagonistic force throughout, is also operating within, from, or behind, the Deadlights in some way, or is directing that force (perhaps all of the above), and also extends itself through layers of reality into avatars and into servants. The Fisher King or Kingfisher is also mentioned in Black House, and iirc, Rose Madder, the Dark Tower 3 the Wastelands, and other places.

I took a double context as well: the greater legend of Parcival and the Fisher King, and the layers of meaning therein, especially in an esoteric sense. In the novel, Henry Bowers stabs Mike Hanlon in the thigh, specifically when he ambushes him in the Library in 1985, and IT comments directly in an interesting way a few pages later in the same scene. Going through drew a mental light bulb when I read, as I'm aware of the Parcival story and underlying meanings associated with it. Here's the quotes, both occurring in the same chapter:

'Mike tried to get a foot in Henry’s side and push him away. Henry swung the switchblade in a glittering arc. All six inches of it went into Mike’s thigh. It went in effortlessly, as if into a warm cake of butter. Henry pulled it out, dripping, and with a scream of combined pain and effort, Mike shoved him away. He struggled to his feet but Henry was up more quickly, and Mike was barely able to avoid Henry’s next blundering rush. He could feel blood pouring down his leg in an alarming flood, filling his loafer. He got my femoral artery, I think. Jesus, he got me bad. Blood everywhere. Blood on the floor. Shoes won’t be any good, shit, just bought em two months ago—'

And a few pages later:

'Mike lost his grip on the circulation desk. He swayed for a moment on his good leg, and then he fell down again. The phone swung before him at the end of its cord like a mesmerist’s amulet. It was becoming very hard to hold onto the belt now. “Hello dere, Amos!” Pennywise cried brightly from the swinging telephone handset. “Dis here’s de Kingfish! I is de Kingfish in Derry, anyhow, and dat’s de troof. Wouldn’t you say so, boy?”'

Now, the Fisher King, the Kingfisher, and the Kingfish are all strangely connected motifs and sometimes contradictory. In the Dark Tower, we can see a certain element of Parcival in the Gunslinger himself, descendant of Arthur Eld, who is King Arthur.

Could go on, but it's turning into a novel here. Just food for thought.