There are Two kinds of snakes that are poisonous.It is the Rhabdophis snakes (keelback snakes) and the Certain Garter Snakes.

Technically there are none. There is no such thing as a "poisonous" snake. They are venomous, not poisonous. Poison has to be ingested, while venom has to be injected.

However, of the approximately 2400 species of snakes in the world, around 600 are classified as "venomous". The bites from some would not affect a human seriously, while others are potentially fatal.

Edit- Actually, the previous comment about poisonous snakes is incorrect, so far there are at least 4 recognized species of POISONOUS snake, including, Rhabdophis tigrinus, Thamnophis atratus, Thamnophis couchii, Thamnophis sirtalis. Most of which aquire their poison from things they eat such as poisonous frogs and keep the venom in glands on their necks.

This question has more than one answer depending on what you mean. 'Poisonous' refers to something that is toxic if eaten or drank, and there are poisonous reptiles - some snakes, such as some gartersnakes (Thamnophis spp.) and Japanese keelbacks (Rhabdophis tigrinus), sequester toxin from their amphibian prey and so would poison you if you ate them. However, most dangerous snakes and lizards are venomous, meaning that if they were to bite you their saliva (venom) would be toxic. The snake with the most toxic venom (meaning that it would take the smallest amount to kill 50% of test mice into which it is injected) is the Inland Taipan (Oxyuranus scutellatus) of Australia. However, this species is not considered very dangerous because it lives in area where almost no humans live. The snake that kills the most people each year is the Russell's Viper (Vipera russelli), which has fairly toxic venom and lives in an area where it commonly comes into contact with humans.

They panthera tigeris or tiger is endangered because it used to be a sport to shoot them.People shot them for fun.Or to sell fur and other body parts.It used to make people proud having a tiger head on the wall but now it's sad and a shame.