Ah, the curmudgeonly fish.
The fish could be Dr. Seuss's take on Spot, the dog in the Dick and Jane series that Seuss is challenging with The Cat in the Hat.
Think about it. At first, we are presented with what looks like "normal" kids in a "normal" home—but instead of a Spot, these kids have a talking fish.
Maybe there really is no normal in Seussville.
Along with fears of Communist invasion, the 1950s was a time of repression. Kites in the house, juggling books, Communism—those were all big no-nos.
A clear foil to the Cat, who's all about YES, the fish embodies that no-no spirit. Louis Menand argues that the fish is "a tin-pot Puritan, and the domestic sphere in which he served as resident superego proved, on closer examination, to be sites of exclusion and oppression" (source). Well, that's one way of seeing it.
But then we get distracted (as usual). The fish is pink. Isn't pink the color of Communist sympathizers? And doesn't he live in a red house, with a bunch of red stuff in it? Hmmm. Maybe the fish doth protest too much. Could he be protecting himself in the case of a summons before The House Un-American Activities Committee. Or could we be reading too much into this? What do you think?
The fish is the children's self-appointed conscience and guardian in their mother's absence. Call him a worry wart, call him grumpy, call him what you will—it won't sway him. He is totally devoted to holding down the fort while Mother is away. He doesn't want a Sixteen Candles situation on his hands.
How does he try to keep order? By talking. A lot. Usually he's saying things like "You SHOULD NOT be here/ When our mother is not" (127-128) and "No! No!" (177) and "No! Not in the house!" (196). You get the idea.
This little fish voices all the concerns that readers—adults and kids alike—might have about the shenanigans taking place. He's totally anti-Cat, who is utterly reckless in contrast to the fish's extreme carefulness. But in the end, their goals line up: clean up the house before Mother gets home. Or else.
Even though the fish can talk, he's still kind of powerless. He can't make the Cat and the Things get out—he's just too little. When things get really hairy and Mother is in sight, he has to force the boy into action, saying, "So, DO something! Fast! […] You will have to get rid of/ Thing One and Thing Two!" (234-241). He can talk the talk, but he just can't walk the walk.
How does this stack up to The Lorax, where the whole point is that animals can't talk and need others to speak for them in order to protect them? The fish is more powerful than those non-talking creatures simply through the power of language—a power we know Seuss loved.
The moral? Teach your fish to talk already.