The size

At birth, boa constrictor measuring only 25-58 cm. These cute little snakes are within a few years - especially if they are female - up to about 3 feet tall giant snakes, which are, incidentally, but not by far the largest in their family: anacondas, rocks, network, amethyst and tiger pythons be significantly larger, and this often in less time. Impressive specimens of Boa constrictor with over 4m length are rare in the countries of origin as well as in European terrariums. This is voralem mind that not all subspecies of boa constrictor ever reach such proportions.
Above all Boa c. constrictor is said to tend to the most extreme lengths. The largest guaranteed total length was 4.2 m.

The much-quoted record length of 18.5 feet (564 cm) is due to confusion with a large anaconda (Eunectes murinus) (Joo 1992). Other reports of similar length, or even much longer individuals of boa constrictors are also based on confusion with anacondas, or simply due to abundant imagination. The last point, the imagination of tourists and locals who like to exaggerate a little left, in some cases even printed sensational reports the size of boas grow to over 10 m - a length that is far from any reality! Boas of over 4 m 40 kg body weight and longer reach, such large animals have a tremendous force and can also cause injury in humans and in unfortunate circumstances, possibly even lead to death.

The intersection of many subspecies at the beginning of the Boa-stance that the majority held in German terrarium "led Mixed Boas", might be one reason why, despite an ideal supply of prey even rare in captivity four-meter-Boas are. There are that is also much smaller remaining subspecies, which are barely larger than a corn snake (Elaphe guttata), which applies even as a beginner snake par excellence. However, these boas are naturally much more massive than a correspondingly large snake. Some local forms of Boa c. imperator remain for example, below 1.5 m in old age, such as many animals coming Ecuador, Nicaragua, Costa Rica and Belize, and some copies of Corn Iceland and the Hog Islands. Also boa constrictor "Mexico Cancun" remains relatively small.