Bulbapedia has an extensive article on it, but it boils down to, in Generation III and on, there is no difference in stats between normal Pokemon and shiny ones.
Generation II (Gold, Silver, and Crystal) is the exception because shininess is determined based on the stats of the Pokemon. Namely:
If a Pokémon's Speed, Defense, and Special IVs are 10, and its Attack IV is 2, 3, 6, 7, 10, 11, 14 or 15, it will be Shiny
But, from Generation III and onward, it is determined based on a secret ID and a trainer ID, so it has nothing at all to do with the stats and will be just like every other Pokemon.
Something fun to note is that if the Male/Female ratio is 7:1, in Generation II, you cannot have a female shiny Pokemon because of the way it is calculated.
Your Trainer ID and Secret ID is generated by the seed that is randomly generated when you start the game for the very first time. It is not defined by your name or gender. There is no possible way to change your IDs without restarting completely or using a save editor or cheating device.
In Generations III, VI and V, your Trainer ID and Secret ID is used in conujunction with a Pokemon's personality to determine shininess. There is a 1/8192 chance of getting a shiny Pokemon.
First, your Trainer ID and Secret ID are XOR-ed (Exclusive OR - one or the other but not both, Ex. 11010111 xor 01101010 = 10111101). That result is saved as variable E.
Then, the encountered Pokemon's two personality values are XOR-ed, with the result saved to variable F.
Finally, E and F are XOR-ed one last time, then checked to see if the final result is less than 8. If so, your encountered Pokemon is shiny.
Here is an example on Bulbapedia, which includes all integer to binary translations.
Best Answer
Missingno is complicated since it is a glitch Pokemon. It has 5 distinct forms, but 2 common ones.
The 2 most common are the top left, and the bottom right. Those are usually called the Red/Blue normal form and Yellow normal form respectively for the games they are found in.
Because of the odd nature of the glitch, Missingno actually varies not only between forms, but within forms as well. Certain forms will have different battle cries, or stats depending on a number of different factors (i.e. how it is encountered), and between the Red/Blue and Yellow forms, it will also have a different type (Normal/Bird and Normal/Glitched respectively). The non-normal forms vary at an even wider level in terms of stats and instead copy those values from a party Pokemon.
The Bulbapedia article linked has a lot more extensive data on the glitch, how it happens, and how to get each type and form (and how they all vary), but the general gist is that with the glitch comes some (expected) oddities and inconsistencies.