If you could invent your own Poké Ball...

[Bidoof Overlord]

The Derp Ball.
The most powerful ball known to mankind.
The kind of ball that makes even MasterBalls faint.
The Derp Ball can catch Bidoof and only Bidoof. The success rate is about 0.25 %.
Why so special you ask? Well, that's the challenge of course.
"Hey look, I caught something with a derp ball!"
"Whoa how did you do that?"

 

[Elaitenstile]

I'd invent the Yield Ball.
It would have a normal catchrate as a Pokéball but is 4x when the Pokémon to be caught is holding an item. It would be really helpful to catch legendary Pokémon like Ho-oh who always hold items (in this case Sacred Ash).

 

[Username Unavailable]

I'd probably invent a ball which has a catch-rate relative to the opponent's speed. I have no idea what to call it, though.

 

[hananas59]

I would invent a discharge ball that is succesful in catching electric types

 

[Altair1]

The 'Dawn Ball' as opposed to Dusk, I'm sure this has already been mentioned though. Greater catch rate during the morning.

I'd invent the 'Prowl Ball' ... It's catch rate is that of an Ultra Ball, however it increases to 4x when the target Pokemon is in a semi invulnerable state while using Fly, Dig, Shadow Force or Dive (not sure if there are others).
It can also target one Pokemon in a wild double battle! (However no catch rate increase).

 

[Golden_spider]

The Mystery Ball, it can turn into ANY pokeball that you can get WITHOUT hacking (like cherish ball or dream ball) here are the %'s of what the Mystery ball can turn into.

Pokeball: 30%
Greatball: 20%
Ultraball: 10%
Masterball: 1% (hey its not going to be easy to get it to turn into a master ball)
Premierball: 5%
Timerball: 5%
Quickball: 5%
Duskball: 5%
Heavyball: 5%
Fastball: 5%
Levelball: 5%
Healball: 4%

And another idea is the Prizeball. It would give out a random item if you catch a pokemon with it (x1 catch rate no matter what) the Prizeball can give out the following.

Common
Potion
Pokeball
Super Potion
Greatball
Random Mail
Repel

Uncommon
Hyper Potion
Ultraball
Super Repel
Escape Rope
Full Heal

Rare
Max Repel
Max Potion
Max Revive
Random TM

Near Impossible
Masterball
Two TM's
Five Berries
Life Orb
Scope Lens
Wide Lens
Expert Belt
Leftovers
Shell Bell
Amulet Coin

 

[SoulRoach]

Maybe a reusable ball.Like if it fails it won't work for the battle, but it will work in another battle.

 

[pokemon-hack]

Sync Ball.
with this ball the connection between trainer and pokemon grows faster

 

[NotThatOneAgain]

Everyone has tried to copy the concept of the Master Ball, none has ever suceeded.

Ultra Ball, Heavy Ball and Premiere Ball. They works well. The Repeat ball is also good.

What could of been made is Rock-Pokèmon that includes water inserted between the layers, so that it cannot escape without hurting itself in the process. Such a ball would have an extremly high success-rate.

A Ball for slow Pokèmon could be invented. Mechanics that shuts the ball quickly and leaves the Pokemon trapped and unable to escape in time.

 

[xseed]

Here comes a huge list:

The Sympathy Ball. the chances of this pokeball catching a pokemon increase each time you fail to catch a pokemon with the ball. The catchrate can even go higher than the ultra ball. of course though it will never reach the state of master.

then I would make a desperate Ball. the chances of a critical catch when using this pokeball increase every 10 turns

the hyper ball. a better pokeball than an ultra ball

the Cold ball which works better in snowy places and also it works better in the hail condition

the Sand Ball. works better in deserts and the sandstorm weather condition.

the Rain Ball. works better in marshes and other wet land spots(doesnt include rivers,oceans,and streams). and also works better in the rain weather condition

the drought ball. works good in plains and also the sunny weather condition

the Snatch Ball. with this pokeball you can get a shot at catching trainers pokemon lol. the catch rate is lower than a great ball however but higher than a pokeball. also the only place these balls are sold are black markets.(this ball wont work on gym leaders and other important battles)

The Petite Ball. Has a higher chance of cathing light pokemon

The Ensnare Ball. Has a higher chance of catching pokemon that have high speed.

The Calm Ball. Has a higher chance of catching pokemon that have a high attack

The Soft Ball. Has a high chance of catching pokemon that have a high def.

The scare ball. Has a high chance of catching pokemon that have a high sp.atk.

The Buff Ball. has a high chance of catching pokemon inflicted with status effects

The Mercess(Play on word Mercyless). Has a high chance of catching pokemon that are on the verge of fainting.

The Leader Ball. the more gym leader badges you have the better it gets. teh catch rate can go beyond an ultra but lower than the hyper ball I made up

The Gourmet Ball. has a higher chance of catching "food pokemon"

The Object Ball. the name says it all. has a high chance of catching "Object Pokemon"

The Gender Ball. Has a higher chance of catching pokemon in relation to the gender of your trainer. for example if your a female trainer you have a high chance of catching Male pokemon and vice versa

*phew. starting to run out of ideas*

The Winter,Fall,Spring,Summer balls. the names tell it all. for example the winter ball has a better chance of catching pokemon in the winter)

okay seriously my brain hurts. thats all for today people. (someone owes me some chocolate lol)

 

[Borngamer]

I got one:

Accuracy Ball: Used to catch a pokemon from group encounters such as hordes. For example, in X version you could use it to catch Seviper before the other Zangooses kill it and Vice Versa in Y version

 

[The Masked One]

I've got one: The Electron Ball: A Pokeball that has an a 100 Percent Catch Rate on Electric and Steel Types. It can only be found in caves, however.

 

[SnowpointQuincy]

Burn Ball. Works on Fire and Burned Pokemon.

 

[AerVaur]

Inverse Ball
The higher the pokemon's health is when you throw it, the higher the catch rate is.

 

[Ace_Master_of_Turtles]

Legend ball catches legedaries better than an ultra ball so you don't have to use 5,000,000 of them to catch F**king every legenday ever!!!!! Braagh!!!!!!!!

 

[~*!*~Tatsujin Gosuto~*!*~]

Since they made balls for Water and bug type Pokemon (the Net ball) they mindless well make balls that catch every particular type of Pokemon. For example a flame ball for fire types, an stone ball for rock type Pokemon etc.


:t354:TG

 

[PumpJack]

Tag Ball.

Follows Entei/Raikou/Suicune around until it catches them.

Tie a GPS on it so you'll know where it is.

 

[lmcde22]

Light Ball: The lower the weight of the target, the higher the catch rate.

(Catch rate of 0.001 on Wailord And then when someone actually gets it, they will be hailed as the ultimate Pokemon catcher ever!)

 

[Ig Pokemon Lover]

Big ball: The bigger the Pokemon the better

 

[Chaos Dragon]

I'd go with...

Stylish Ball - Increased capture rates on Pokemon sharing similar traits with the Pokemon currently available in your Pokemon list and increases its happiness rate based on the styles. (For example: it'd be more likely to catch a heavy Pokemon if you have a heavy Pokemon, a Fire type if you have a Fire type, a cute Pokemon if you have a cute Pokemon, a legendary if you already have a legendary Pokemon, etc., and happiness would work similarly too.)

Illusive Ball - Increases capture rate on Pokemon weak to Psychic so long as you are currently using a Pokemon with Psychic as their main type.

Seasonal Balls (Spring, Summer, Fall, & Winter) - Each one would be more effective when used during their respective season and would give the Pokemon a regen effect while outside of battle during their respective season.

Boomerang Ball - Doesn't have a special catch rate, but what makes it special would be that it's shaped and throwable much like a return boomerang.