Exotic food
Eggs are always a popular snack in Asia, especially in Northern Vietnam. More desired than ordinary eggs, are the lightly blue eggs with nearly-developed embryo inside, so-called hột vịt lộn. Normally it is duck eggs that are half-hatched, i.e. fertilized but only partway incubated. Some have embryos that are in a very early stage, while others have almost fully developed embryos with feathers, soft bones and beak. Though the taste is not very different from an ordinary egg, the texture might put you off.
The dangerous spiky durian fruit is probably the fruit most people have an opinion about, those who know it. The smell from an opened durian is so intense, foul and nauseating that many places through Southeast Asia have a ban on eating them in public. The taste, on the other hand, is very sweet, with a buttery texture (some will call it disgusting). It is no wonder that Asian people say the durian smells like hell and tastes like heaven. Try small bits in the beginning and work you way up. If you are hooked, you can even indulge on durian candy, durian icecream and durian chips - and even durian flavored condoms in Indonesia.
The Mekong Delta is where the Mekong River flows into the sea through a maze of side rivers. It is the most fertile region in Vietnam and the relative small area manage to produce half of Vietnam's rice production along with a overwhelming range of vegetables and exotic fruits. The markets in Mekong are therefor packed with colorful fruits like rambutan, dragon fruit, mangosteen and of course the smelly pointy durian. But the people in the Mekong are also known for their taste for, well, pretty much anything. Frogs, snails, turtles, rats, snakes, scorpions, you name it. If they can catch it, they eat it. So the local market in the trading town of Vinh Long can have the feeling of a zoo but don't be fooled, everything here is for consumption.
The South Vietnamese people are known to eat pretty much anything, also scorpions. The poor animals are fried and served with lemon and salt. You eat the whole thing, including the stinger and claws, and we assume the frying process annihilate any poison. The taste is on the doll side, since it is mostly just a crunchy exoskeleton - and we don't know anything about the nutritious value.
There are restaurants in Vietnam that specialized in snake meat. Here you can pick your own snake from a cage. The handler will then bring the snake alive to your table, smack it in the head and slice it open. The blood will be drained into a glass with rice wine and then served to you, along with the heart which will still be pumping. The rest of the snake will be brought to kitchen, where it will turn into several snake dishes, like spine soup and snake skin cracklings. Every single bit of the snake is used and it is believed that each part have some health improvement properties, like eating the pumping heart will give strong sexual powers.
Vietnam is a great place to try some new food sources. Either unusual animals, or just unusual parts of animals - like uterus of pig.
Why would anyone eat a wasp?... well, probably because you can. The young wasp larvae are taken right from their cocoon and fried. You probably don't want to get stuffed on wasp larvaes, but as a snack, they are actually not too bad - like soggy french fries.