The Unseen is a term used for some of the first BattleMech designs from the original game. These designs, longtime favorites of BattleTech fans, were based on mecha found in the Japanese anime series' Super Dimension Fortress Macross, Fang of the Sun Dougram and Crusher Joe.
Legal difficulties prohibited FASA from displaying any more pictures depicting these 'Mechs, although they were often freely mentioned in novels and books, and their rules remained legal. Thus, these 'Mechs remained unseen until the publication of Technical Readout: Project Phoenix, which presented "redesigns", allowing them to be used freely once again.
On 24 June, 2009, it was announced that Catalyst Game Labs had secured the permissions needed to utilize the original "unseen" artwork for these designs again.
Shortly after the return of the "unseen" BattleMechs was announced, the BattleTech: 25 Years of Art & Fiction PDF was pulled from circulation. Managing editor Randall Bills made a statement on Catalyst Game Labs' website on August 10th, 2009 explaining the move. An error was made in negotiating the distribution rights for some of the images. Twelve Unseen images, those originating from Macross, were again pulled from circulation and will remain unseen, due to their exclusive distribution rights (within the United States) belonging to another company (Harmony Gold). Whether or not these images will be licensed or purchased in the future remains to be seen. The tone of the article was doubtful.
The Unseen 'Mechs, and their origins, are:
 From Crusher Joe
- Corsair aerospace fighters - Siren :Reseen as of Record Sheets: Operation Klondike
- Samurai aerospace fighters - Harpy
- Sparrowhawk aerospace fighters - mix of Siren & Harpy
- Galleon Tank - Galleon tank
- Leopard Dropship - Minerva
 From Macross
- VF-1 Valkyrie
This 'Mech from the Super Dimension Fortress Macross series normally transformed into the three combat modes recognized in BattleTech by Land Air 'Mechs. Within the BattleTech game this one vehicle was split into distinct non-transformable 'Mechs models and LAM models. The LAMs, true to their artistic origin, could transform into aerospace fighter, hybrid and 'Mech mode.
- Stinger VF-1A
- Stinger LAM - LAM model of above, illustrated in LAM or Hybrid mode
- Wasp VF-1S
- Wasp LAM - LAM model of above illustrated in LAM or Hybrid mode
- Super Wasp
- Valkyrie VF-1S
- Phoenix Hawk - VF-1S with FAST Packs
- Phoenix Hawk IIC - VF-1S :Reseen under a new agreement
- Phoenix Hawk LAM - LAM model of above illustrated in LAM or Hybrid mode
- Crusader - Armored VF-1A, 
- Falcon :Reseen as of Record Sheets: Operation Klondike (From BattleDroids)
- Firebee (From BattleDroids)
- Hornet (From BattleDroids)
- Zentraedi "Regult" Tactical Battle Pod
- HWR-00-Mk. II Monster Heavy Weight Destroid
- MBR-07-Mk II Spartan Main Battle Destroid
- MBR-04-Mk VI Tomahawk Main Battle Destroid
- MBR-04-Mk X Defender Anti-Aircraft Defense Destroid
- SDR-04-Mk XII Phalanx Space Defense Destroid
- Zentraedi "Glaug" Officer's Battle Pod
 From Dougram
- Shadow Hawk :Reseen as of Record Sheets: Operation Klondike
- Shadow Hawk IIC :Reseen under a new agreement
- H8 Roundfacer
- F35C Blizzard Gunner
- T10B Blockhead
- F4X Ironfoot
- F44A Crab Gunner
- HT128 Bigfoot
 From Victor Musical Industries
These have been temporary Unseen, until becoming :Reseen.
- Conjurer (Hellhound)
- Glass Spider (Galahad)
- Howler (Baboon)
- Bane (Kraken)
- Vapor Eagle (Goshawk)
- Black Python (Viper)
- Stone Rhino (Behemoth)
- Incubus (Vixen)
- Grand Crusader
- ↑ Catalyst Game Labs website, "Sometimes Things Just Don’t Go As We Want Them To"
- ↑ In some artwork such as in The Fourth Succession War Scenarios, the Crusader is depicted with a modified VF-1J head.