The Ballad of Big Al
The Ballad of Big Al (distributed in the North American market as Allosaurus: a Walking with Dinosaurs Special) is a two episode series of Walking with Dinosaurs specials following the real-world Allosaurus (Allosaurus fragilis) specimen "Big Al". It first aired on BBC One in the United Kingdom during Christmas 2000.

Plot 

The special begins at the University of Wyoming, showing the bones of a sauropod followed by an Allosaurus named Big Al. After the ghost of Big Al wanders the museum passing by his own skeleton and a nest of fossilized eggs, the film then travels back in time to 145 Mya showing a similar nest. Al and his siblings hatch and are helped out of the nest by their mother. She brings them to a river bank and the hatchlings start to hunt for insects. When the mother leaves the hatchlings temporarily, a year-old Allosaurus comes out of hiding and kills one of them (luckily, the victim was not Al).

Al is then shown at the age of two years. He tries to hunt a flock of Dryosaurus . He has not yet learned how to ambush so he fails to kill one of the swifter, smaller dinosaurs. Later, he snatches a lizard from a branch to keep him satisfied. Al comes across a dead Stegosaurus  and an Allosaurus waiting for death in a pit of sticky mud. Meanwhile, a female Allosaurus, attracted to the Stegosaurus carcass, also gets stuck. She struggles to free herself, but fails. Al luckily avoids the same fate as he had learnt to avoid carrion and the large carnivores that it usually attracts. Unable to escape, the trapped Allosaurus pair die of exhaustion, their corpses left to Anurognathus.

Three years pass, and a herd of Diplodocus are migrating across the prehistoric salt lake. Al, now 30 feet (9 meters) long, is joined by several other Allosaurus and they manage to panic the herd into leaving a weakened sick individual behind. But as the Allosaurus gather for the kill, Al is struck down by the neck of the Diplodocus. The pack decides wait for a few hours until the Diplodocus is brought down by heat exhaustion and his illness. Though they feed, within the hour an adult female Allosaurus scavenges the kill. Al takes some remnants of the carcass for himself and leaves, trying to find a safer place to eat.

A year passes by, and Al, now 33 feet (10 metres) long with the crests over his eyes reddening, is shown drinking at a pond. His presence however makes other dinosaurs around the pond nervous and the smell of blood he brings with him puts off a pair of Stegosaurus that were attempting to mate. Away from the pond, he discovers the scent of a nearby female Allosaurus and issues a mating call. She is not interested, but Al's inexperience shows, causing him to get too close for her comfort, and the female attacks him. Al is lucky enough to escape from the ensuing fight with his life, although he sustains injuries to his right arm as well as smashed ribs. Later the dry season comes, and Al is attempting to hunt a flock of Dryosaurus. Whilst ambushing them however, a log falls in his path which he trips over and ends up breaking something in his right foot. As the dry season turns to a drought, Al's limp from the fall gets worse and his right middle toe -which he broke in the fall- has become badly infected. Soon, unable to hunt, he dies in a dried-up riverbed, where two hatchling Allosaurus are hunting for bugs and come across his emaciated carcass. He is said not to have reached full size, dying as a mature adolescent and that the process of his fossilisation was so perfect it preserved even the injuries and diseases he sustained in his lifetime including -amongst others- lumps where his ribs healed after their break and the raging infection on his middle toe.

Episodes

American Version
The American version was renamed Allosaurus: A Walking with Dinosaurs Special, along with combining the evidence with Al's life. Also they took out the one of the trapped Allosaurus and the birds and reptiles behavior, and shots of Al living in the 21st Century.

Critical reaction 
The Ballad Of Big Al won two 2001 Emmy Awards, including Adelphoi Music Ltd's Andrew Sherriff and Ashley Bates for Outstanding Sound Editing for a Non-Fiction Program.

Merchandise

Book Adaptation
A children's book was made, called Allosaurus! The Life and Death of Big Al, and it differs from both the American and UK versions in some aspects. 
 
The Stegosaurus was shown dead in the show, while it was alive and struggling (trying to fight off the Allosaurus pair) and soon died in the book.
In the show at the second and sixth years, Al is hunting Dryosaurus. In  the book he is hunting Othnielia.
Al tripped on a log in the show, while he tripped on a mound of dirt in the book.

BBC game
The BBC launched an online Role-Playing Game involving Big Al, now replaced by the Planet Dinosaur online game.