To my mind, nothing is more representative of congealed thought than Jello. Making a jello cake could be as easy as pouring it into a mould (layered or unlayered) and adding some decoration on top. But I want something a bit more weird and wonderful. I'm going to stick with the jello idea though. Colour is an important consideration. What colour should it be and what would that colour mean? Or perhaps more important than colour, what flavour? What shape?
Musing on the word shark: I think of oceans, sea water, seaweed and fishy-ness. I could make a miso jello and stir in nori flakes, some chunks of white fish, maybe finish it off with a drizzle of fish oil. I could even cut it into a shark silhouette. Maybe not… Shaping it into a shark seems too literal a representation. It would certainly say ‘shark’ but it just doesn’t say cake to me...