The Steel Titan, also know as Registeel, King of the Jungle, Cyborg (Teen Titans) or "I'M THE JUGGERNAUT BITCH!!" is a Summoning familar that takes 5 years of training, 9/10ths of the World's Funds and a lifetime supply of dry Pot Noodle to obtain.
The Steel Titan originally had a movie career, getting his first cameo appearance as an extra in Star Wars. He also applyed to star as Bender in Futurama, but was fired on the set after the director found Rule 34 hidden on his hard drive.
10 years and 6000 Big Macs later, Steel Titan was given a part in the movie "Lucario and the Mystery of Mew", which involved FIRING HIS LAZOR at a dog while making Atari 2600 sound effects. After realising that only 5 people ever watched it (even via P2P download), Steel Titan decided to delete his system32 and throw himself into Bill Gate's scrapheap.
Later, when Jagex were looking for recycled scrap metal to build World 170/171, they came across a discarded robot shell, and sent it to the programmer team. Unfortunately since Jagex's programmers are nothing more than monkeys on typewriters, the titan became self-aware, and kept asking players if they wanted to kill themselves in an epic battle (Although, how you can kill something that has no life to begin with is beyond me...
The Steel Titan uses attacks such as Metal Claw, Iron Defence, Flash Cannon and Giga Impact, He can also use a special move called "Steel of Legends" which is about as accurate as Gordon Brown's prediction of the global economy. Trying to ruin him is physically impossible as he is made out of diamond and kryptonite. (Besides, you are more likely to get ruined by the owner first) When the Steel Titan is summoned, the owner will be greeted with a swarm of "ZOMFGBBQ11111!!ican'tbelieveit'snotbutter!!!1!!one!111!ITS REGISTEEL TITAN!!" and "do sumon emot pl0x???", while the other half of the players will be a sack of idiots trying to attack it in Castle Wars while the flag holder orders something from Pizza Hut, as everyone seems to have forgotten he exists.