| Pokedex Entries: |
| Red | Because it store several kinds of toxic gases in its body, it is prone to exploding without warning. |
| Blue |
| Yellow | In hot places, its internal gases could expand and explode without any warning. Be very careful! |
| Gold | Its thin, filmy body is filled with gases that cause constant sniffles, coughs and teary eyes. |
| Silver | The poisonous gases it contains are a little bit lighter than air, keeping it slightly airborne. |
| Crystal | If one gets close enough to it when it expels poisonous gas, the gas swirling inside it can be seen. |
| Ruby | If KOFFING becomes agitated, it raises the toxicity of its internal gases and jets them out from all over its body. This POKéMON may overinflate its round body, then explode. |
| Sapphire | KOFFING embodies toxic substances. It mixes the toxins with raw garbage to set off a chemical reaction that results in a terribly powerful poison gas. The higher the temperature, the more gas is concocted by this POKéMON. |
| Emerald | Getting up close to a KOFFING will give you a chance to observe, through its thin skin, the toxic gases swirling inside. It blows up at the slightest stimulation. |
| FireRed | Its thin, balloon-like body is inflated by horribly toxic gases. It reeks when it is nearby. |
| LeafGreen | Because it store several kinds of toxic gases in its body, it is prone to exploding without warning. |
| Diamond | Lighter-than-air gases in its body keep it aloft. The gases not only smell, they are also explosive. |
| Pearl |
| Stadium 1 | A POKéMON that is a like a thin-skinned balloon filled with a highly toxic gas. Known to occasionally explode. |
| Stadium 2 | Its thin, filmy body is filled with gases that cause constant sniffles, coughs and teary eyes. |
| TCG | Koffing: First discovered in a weapons factory, this Pokémon can now be found almost anywhere. |
