During the early eighties a, large number of fake Microman, Diaclone and other pre-Transformers were sold in the US and other countries. Often a bootleg version is much more frequent than the real version, so watch carefully when buying a certain pre-Transformer. Especially the Taiwanese bootlegs are almost indistinguishable from the originals. Sometimes the only differences are the lack of a copyright mark and the packaging. In some occasions even the package is almost exactly the same as the original, with as only difference that there are no signs of the original producers.

Examples:

Micro Change bootlegs:
These are very common in the US. I've seen bootleg versions of Microx (Reflector. Be careful when buying a Reflector. This bootleg is almost identical!), MicroScope (Perceptor), the cassettes (in cassette cases with poorly translated English writings on them), the Meteor Robos, Gun Robos and perhaps some others. Most of these bootlegs were sold in packages that were copied from the original Japanese packages, but with the text (poorly) translated into English.

Diaclone bootlegs:
The same story as with the Microman toys. I've seen fakes of the Construction Vehicle Robos (Constructicons), Dinosaur Robos (Dinobots) and Triple Changers.

Macross:
There are various bootlegs of the Valkyries. One of the most known ones are the Korean bootlegs VF-1J Valkyries made by Joon's, which are still available. They come in packages almost identical to the originals. The toys themselves are of a considerable lower quality than the originals. Another example is a bootleg version of the Super Valkyrie. A good description of this one can be found at the "Valkyrie Factory" page.

Bootleg "toylines":
 
Insectbot: These are bootleg versions of the Beetras toys, the forerunners of the Deluxe Insecticons.
Kingdam: Bootleg versions of Diaclone F-15 (Starscream), Microman MC-07, Diabattles, Browning and others.

 

Bootleg version of the Diaclone Jet/Heli Triple Changer.