There is a species of snake called bird snakes

The twig or bird snakes of the genus Thelotornis are a group of back-fanged snakes in the family Colubridae. All species have slender and elongated profiles, long tails, narrow heads, and pointed snouts. The eyes of each species have horizontal pupils, shaped like keyholes, which give twig snakes binocular vision. Twig snakes are greyish-brown with faint light and dark markings. When threatened, they inflate their throats to display bold black markings between the scales.
The twig snake is one of the several back-fanged colubrids whose bite is highly venomous and potentially fatal. The venom is hemotoxic, and although its effects are very slow, and bites are rare, no antivenom has been developed and several fatalities (such as Robert Mertens) have occurred.
The African twig snakes are distinctive in appearance and unlikely on that continent to be mistaken for any other snake, if indeed the observer notices them. Preying on lizards, frogs, and sometimes birds, they conceal themselves in trees, but often at a low enough level to be able to also strike at terrestrial prey, which they may swallow upwards after killing. Their cryptic coloration and apparent ability to freeze or sway gently, as chameleons do, like a twig on a tree (hence the name), makes them hard to spot. Indeed, they may be more abundant in areas than is immediately obvious.
Thelotornis is characterised by a depressed and flat head, keyhole-shaped pupils, and in T. kirtlandii, a projecting canthus rostralis which forms a shallow loreal groove on each side of the head. This allows a certain amount of binocular vision to the snake. In appearance, the head at least is unlikely to be mistaken for any other African snake. Other characteristics include a very long tail and large back fangs. The iris in T. capensis and T. kirtlandii is yellow, and presumably therefore also in T. usambaricus. The subspecies of T. capensis, T. c. mossambicanus is sometimes considered a distinct species.

Anaconda refers to a snake found only in South America

Although the name refers to a snake found only in South America, the name commonly used in Brazil is sucuri, sucuriju or sucuriuba. The South American names anacauchoa and anacaona were suggested in an account by Peter Martyr d'Anghiera but the idea of a South American origin was questioned by Henry Walter Bates who, in his travels in South America, failed to find any similar name in use. The word anaconda is derived from the name of a snake from Ceylon (Sri Lanka) that John Ray described in Latin in his Synopsis Methodica Animalium (1693) as serpens indicus bubalinus anacandaia zeylonibus, ides bubalorum aliorumque jumentorum membra conterens. Ray used a catalogue of snakes from the Leyden museum supplied by Dr. Tancred Robinson but the description of its habit was based on Andreas Cleyer who in 1684 described a gigantic snake that crushed large animals by coiling and crushing their bones. Henry Yule in his Hobson-Jobson notes that the word became more popular due to a piece of fiction published in 1768 in the Scots Magazine by a certain R. Edwin. Edwin described a tyger being crushed and killed by an anaconda when in fact tigers never occurred in Sri Lanka. Yule and Frank Wall noted that the snake was in fact a python and suggested a Tamil origin anai-kondrameaning elephant killer. A Sinhalese origin was suggested by Donald Ferguson who pointed out that the word Henakandaya (hena lightning and kanda stem/trunk) was used in Sri Lanka for the small whip snake (Ahaetulla pulverulenta) and somehow got misapplied to the python before myths were created.