Verechelen (IPA: [ʋʲɘrʲɛʑʲɘˈlʲɛn]; Chuvash: Вӗрӗҫӗлен Vĕreśĕlen, or Вӗриҫӗлен, Вӗриҫлен, Вриҫлен; Russian: Вереселень), also known as Chuvash dragons,^[1] are winged fire-breathing and shapeshifting dragons. The legend originates with the ancestral people of the Chuvashians.^[1]

The name means 'invisible snake'. These differ from their Turkic counterparts (such as Zilant), as they are supposed to reflect the mythology of Volga Bulgaria.

Chuvash dragon is Věri Şělen (Вӗри Ҫӗлен, lit. "fire snake").^[1] Like the Russian Gorynych, the creature has multiple heads and leaves a fiery wake when flying. The wood demon Arşuri often turns into a snake, but more often he looks like Şüräle.

According to one legend, when the Bulgars came to found the town of Bilär, they discovered a big snake living in the area. When they decided to kill it, the snake begged for peace and asked Allah to give him wings. Once he got wings, the snake flew away from Bilär.

Another great snake, or dragon, was said to live in a pagan tower temple at Alabuğa. Although the Bulgars adopted Islam as early as the tenth century, the snake allegedly survived until the time of Tamerlane's invasion.

Ibn Fadlan, who visited Volga Bulgaria in the 10th century, referred to numerous snakes, especially on trees. Once he saw a big fallen tree, which was longer than a hundred ells. Ibn Fadlan wrote that he'd seen a big snake at the trunk that had been almost as large as the tree itself. The Bulgars allayed his fears, assuring him that the snake was not dangerous.

• List of dragons in mythology and folklore

• Чӑваш халӑх пултарулӑхӗ: Мифсем, легендӑсем, халапсем. — Шупашкар: Чӑваш кӗнеке изд-ви, 2004. (in Russian)