Metagross seems to draw influence from both robots and supercomputers, given its mechanically structured appearance and considerable intelligence. It's 4 legs may give it a similar body structure to that of a spider.
Metagross is favoured by a lot of competitive players when it was initially introduced.
As another Pseudo-Legendary Pokémon, Metagross has some strong stats that can allow it to run any set at will, but it is generally used as a powerful sweeper. It has access to a lot of powerful attacks, like Meteor Mash, Earthquake, Zen Headbutt, and even Explosion. Metagross has Clear Body as it's primary Ability, which can protect it from moves like Intimidate and Scary Face.
It also received a Mega Evolution in Ruby and Sapphire's remakes. Mega Metagross gains the Tough Claws Ability, allowing it to make excellent use of it's diverse physical movepool.
Metagross is not without it's faults, despite the solid coverage it has at it's disposal. As a physical attacker, it does not favour the Burn status, which can easily cripple it's ability to sweep. From Generation 6 onwards, it now takes super effective damage from Ghost and Dark Types, since Steel lost it's resistances to the aforementioned two Types.
Metagross is considered by many to be the most iconic Pokémon of Steven Stone, a well-respected Trainer and Champion of Hoenn.