The Trap Door is a children's claymation-style animated series, shown in the United Kingdom in the mid-1980s. It was created by Terry Brain and Charlie Mills.

The main character, Berk (a short blue creature), his pet spider Drutt, and his friend Boni (a talking skull), live in a castle in "the dark and nasty regions", where Berk serves The Thing Upstairs (who never leaves his room, and is consequently never seen, although his bellowing voice is frequently heard). In addition, Berk must guard the trapdoor in the floor of the servants' quarters, which leads to dark and mysterious caverns from which, every episode, something will emerge... Though mostly hostile or mischevious, occasionally a helpful or friendly creature did emerge, the large red creature named Rog was one example.

The series ran for two seasons and numbered 40 episodes. Each episode was around five minutes long. All the character voices were provided by Willie Rushton.

Although selected episodes of the series were available on various videotapes in the UK at various times, only a rare double videocassette released in Canada at one point actually contained every single episode. It was not until 2005 that all the episodes were finally made available on DVD in the UK.

The television series spawned a video game in the mid-80s called The Trap Door and a sequel called Through The Trap Door. These games (available for the ZX Spectrum and the Commodore 64) probably introduced nearly as many people to the quirky blue creature as the series did. They can now be played on a modern computer system using various emulators.

There have been many Toa over the years. They can come in many forms, but two things they all have in common is a Kanohi mask of power on their face and the desire to do good. They all also posess the ability to create or control a certain element. The six below are only a few of the ones that Matoran have seen over the years.

The Toa on Mata Nui are six elemental beings, likened to spirits sent to protect Mata-Nui from evil. The Toa were originally called to earth by the collection of the Toa Stones. Later, when exposed to protodermis, the Toa turned into Toa Nuva.

Tahu is the Toa of Fire and the leader of these warriors. Tahu is the boldest and most courageous of the Toa; however, this trait often manifests itself as hot-headedness and aggression. His Kanohi Hau is a Mask of Shielding.

Kopaka is the Toa of Ice. Kopaka's intelligence and cunning are matched only by emotionlessness: he almost never shows any passion or loses his cool, preferring to hide his feelings behind a layer of silence as thick and impenetrable as the ice sheets covering the mountains of his homeland, Ko-Wahi. Kopaka rarely gets along well with the other Toa. His Akaku is a Mask of X-Ray vision.

Gali is the Toa of Water, and the only female Toa. Though she personifies the deepest, darkest oceans, there is an aura of warmth and caring surrounding Gali that the other Toa do not possess. Though her preference for peace would make her ill-suited to lead the Toa, she has proven herself many times in battle. She wears the Kanohi Kaukau.

Pohatu is the Toa of Stone, and the binding force that ties the other Toa together. The witty, chivalrous Toa is above all things a people person, and he maintains friendships with each of the other Toa even when they can't agree with each other. Though Pohatu is generally slow-moving, his Kanohi Kakama (the Great Mask of Speed) gives him the power to move faster than the eye can trace.

Lewa is the Toa of Air. As the youngest Toa, he is vulnerable. Lewa is an especially playful and mischevious spirit who thinks nothing of pulling innocent pranks on his villagers and fellow Toa; some have argued that this will be his undoing unless he learns when he's taken a joke too far. His Miru allows him to levitate himself.

Onua is the Toa of Earth, and the most mysterious of the Toa. Little is known about this Toa, who spends most of his time underground in his subterranean realm of Onu-Wahi. While this wise Toa has much to contribute to the group, he often shies away from drawing attention to himself. Still, Onua has a combination of down-to-earth sense, powerful natural instinct, and sheer brute strength from or without his Pakari, which makes him useful.

In the distant past, two new heroes awake! Toa Iruini served the Brotherhood of Makuta, but defeated Makuta after learning the Brotherhood had turned corrupt. Then Iruini quit his team, believing they spent too much time on huge menaces and not enough on ever-present dangers. So he escaped the ambush that took most of his team and allied with Norik on a quest to save Gaaki, Pouks, Kualus and Bomonga from Roodaka. He used his healing spinners, element of wind, and Kanohi Kualsi.