| Pokedex Entries: |
| Red | While lulling its enemies with its vacant look, this wily Pokémon will use psychokinetic powers. |
| Blue |
| Yellow | Always tormented by headaches. It uses psychic powers, but it is not known if it intends to do so. |
| Gold | It has mystical powers but doesn't recall that it has used them. That is why it always looks puzzled. |
| Silver | If its chronic headache peaks, it may exhibit odd powers. It seems unable to recall such an episode. |
| Crystal | The only time it can use its psychic power is when its sleeping brain cells happen to wake. |
| Ruby | PSYDUCK uses a mysterious power. When it does so, this POKéMON generates brain waves that are supposedly only seen in sleepers. This discovery spurred controversy among scholars. |
| Sapphire | If it uses its mysterious power, PSYDUCK can't remember having done so. It apparently can't form a memory of such an event because it goes into an altered state that is much like deep sleep. |
| Emerald | When its headache intensifies, it starts using strange powers. However, it has no recollection of its powers, so it always looks befuddled and bewildered. |
| FireRed | It is constantly wracked by a headache. When the headache turns intense, it begins using mysterious powers. |
| LeafGreen | While lulling its enemies with its vacant look, this wily Pokémon will use psychokinetic powers. |
| Diamond | If its usual headache worsens, it starts exhibiting odd powers. It can't remember doing so, however. |
| Pearl | It never remembers using its odd powers, so it always tilts its head in puzzlement. |
| Platinum | Overwhelmed by enigmatic abilities, it suffers a constant headache. It sometimes uses mysterious powers. |
| Stadium 1 | Appears unaware and totally vacant. However, if its chronic headache worsens, it starts exhibiting peculiar powers. |
| Stadium 2 | It has mystical powers but doesn't recall that it has used them. That is why it always looks puzzled. |
| TCG | Psyduck: It is often seen holding its head in its paws, as if it were suffering from a headache. |
| Psyduck: Although possessed of great mental powers, it doesn't know how to use them. |
| Psyduck: While lulling its enemies with its vacant look, this wily Pokémon will use psychokinetic powers. |
