On the way home from Tesco, having bought some food, I began to contemplate George Romero's 'Dawn of the Dead', in particular a sequence in which one of the heroes, having been bitten by a zombie, realises that his final hours are upon him; "You'll take care of me, when I go?" he asks his best friend, "I don't want to be walking around... like that". "I'm going to try not to come back", he says.

"I'm going to try... not to".

It's no use, of course, and he comes back as a zombie, a bewildered, scared zombie whose brains are promptly blown out, off-screen, by his pal. I am not an expert on religion, but I believe that many religions hold reincarnation as a central plank of their belief structure, albeit reincarnation as an animal or living person rather than as a zombie. And I got to thinking, as I walked up the hill.

Assuming that one must return as an animal, I believe that most people, having given that matter a little thought, would rather come back as a dolphin. Dolphins are clever like us, live as long as us, and eat fish - just like us. Raw fish, it has to be said, but it would easier to get used to eating raw fish than eating worms, or dung, for example. Indeed some otherwise normal human beings actually enjoy eating raw fish, although it must be said that some human beings derive sexual pleasure from watching cows defecate.

Are the sushi-eaters themselves reincarnants of dolphins? Turtles live longer than people, but they live precarious lives (and so do dolphins, so - trawlermen! - put those nets away!). Whales are very similar to dolphins, but they aren't sexy. Dolphins are sexy, in both the 'fast sports car' sense - dolphins are a great piece of design - and in the other sense, and of course as a dolphin you yourself would feel no shame in looking at lady dolphins in the other sense.

Dolphins are mammals, and do not lay eggs. Instead, they lay men, and drink air. If they laid eggs, the eggs would sink, and the baby dolphin would be crushed by the water pressure or, if the egg was incompressible, the hatched baby dolphin would drown on his or her way to the surface. Therefore the egg would need an air pocket in order to float on the surface of the water; eggshells are permeable, and the baby dolphin could suck very hard in order to draw air through the shell, which would have the positive effect of increasing the dolphin's lung power.

The obvious problem however is that the eggshell, floating on the water, would become a magnet for seagulls, who would peck at the shell and eat the baby dolphin, just as we eat the unborn young of chickens. There's nothing to be ashamed of in that. America eats its young. Those who survive are either strong, or rancid, or lucky; same thing. It's all about strategies for survival. You can either be strong, or charming, or repulsive, or funny, or just plain lucky. You're either Cary Grant or Lemmy or John Candy, all successful in their own fields, all very different men.

Therefore the dolphin's eggs would have to have a thick shell, which leads to a further problem, in that the baby dolphin would be unable to escape after having come to term. The solution would be to provide the baby dolphin with an 'escape hatch' on the underside of the shell, by making the shell thinner there, and putting the air pocket at the thicker end of the shell (the egg would probably resemble a chicken egg, floating fat-side-down in the water, with only the tip visible above the surface).

The egg would thus be impregnable to all but noxious gas, and of course you have to accept certain risks. The seagulls could land on the top and make their nest there, perhaps blocking air ingress, in which case the egg would have to be either very slippery or very pointy in order to dissuade the birds.

So there you have it. Dolphin eggs would be the shape of pyramids. Granted, they would not be indestructible, but nothing in nature is indestructible, not even the aliens from the film 'Alien'. I can't imagine the degree of pain to which the mummy dolphin would be subjected as she gave birth to this pointy egg, Iron Maiden's 'Where Eagles Dare' - from their fourth album, 1983's 'Piece of Mind' - was based on the film of the same name, and even includes a mock 'machine gun battle' with sound effects. Perhaps coincidentally, it vaguely resembles Queen's 'Battle Theme' from their soundtrack to the 1980 film 'Flash Gordon'.