| 2 | Gold | Its entire body is shielded by a steel-hard shell. What lurks inside the armor is a total mystery. |
| 2 | Silver | It remains immovably rooted to its tree. It scatters pieces of its hard shell to drive its enemies away. |
| 2 | Crystal | Usually found hanging on to a fat tree trunk. It shoots out bits of its shell when it sees action. |
| 2 | Stadium 2 | Its entire body is shielded by a steel-hard shell. What lurks inside the armor is a total mystery. |
| 3 | Ruby, Sapphire | Forretress conceals itself inside its hardened steel shell. The shell is opened when the Pokémon is catching prey, but it does so at such a quick pace that the shell's inside cannot be seen. |
| 3 | Emerald | It keeps itself inside its steel shell. The shell is opened when it is catching prey, but it is so quick that the shell's inside cannot be seen. |
| 3 | FireRed | It remains immovably rooted to its tree. It scatters pieces of its hard shell to drive its enemies away. |
| 3 | LeafGreen | Its entire body is shielded by a steel-hard shell. What lurks inside the armor is a total mystery. |
| 4 | Diamond, Pearl, Platinum | It is encased in a steel shell. Its peering eyes are all that can be seen of its mysterious innards. |
| 4 | HeartGold | Its entire body is shielded by a steel-hard shell. What lurks inside the armor is a total mystery. |
| 4 | SoulSilver | It remains immovably rooted to its tree. It scatters pieces of its hard shell to drive its enemies away. |
| 5 | Black, White, Black 2, White 2 | It is encased in a steel shell. Its peering eyes are all that can be seen of its mysterious innards. |
| 6 | X | It is encased in a steel shell. Its peering eyes are all that can be seen of its mysterious innards. |
| 6 | Y | It remains immovably rooted to its tree. It scatters pieces of its hard shell to drive its enemies away. |
| 6 | Omega Ruby, Alpha Sapphire | Forretress conceals itself inside its hardened steel shell. The shell is opened when the Pokémon is catching prey, but it does so at such a quick pace that the shell's inside cannot be seen. |
| 7 | Ultra Sun | When something approaches it, it fires off fragments of its steel shell in attack. This is not a conscious action but a conditioned reflex. |
| 7 | Ultra Moon | In the moment that it gulps down its prey, the inside of its shell is exposed, but to this day, no one has ever seen that sight. |
