1) Bird’s nest – China

Edible bird’s nests are bird nests created by swiftlets, using solidified saliva. They are particularly prized in Chinese culture due to their rarity, supposedly high nutritional value, and flavour. Edible bird’s nests are among the most expensive animal products consumed by humans, with nests being sold at prices up to about US$3,000 per pound, depending on grading. The nests have been used in Chinese cooking for over 400 years, most often as bird’s nest soup.
2) Tuna eyeballs – Japan

It looks disgusting but it actually tastes good as it tastes pretty similar to squid or octupus. These are most eaten Japan
3) Hákarl – Iceland:

The rotting carcass of a Greenland or basking (Somniosidae) shark. It’s buried underground in a shallow pit and pressed with stones so the poisonous internal fluids that allow it to live in such cold waters can be drained out making the meat safe to eat. After this it’s hung out to dry before being cut into strips and served. With a smell that’s described as ammonia-rich and a strong ‘fishy-flavour’.
4) Shiokara – Japan

A dish made of pieces of meat taken from a selection of sea creatures, served in a brown, viscous paste of their own salted and fermented viscera. Oh and it’s eaten raw.
5) Balut – Philippines

A developing duck embryo that’s boiled alive in its shell. As well as sounding incredibly harsh, it looks incredibly unappetising. Still, it’s a common street food and is usually served with beers.
Source:
https://www.hostelworld.com/blog/the-50-weirdest-foods-from-around-the-world/