Reproduction

Various reproduction methods for the Transformers species have been demonstrated across various continuities.

Mechanical construction
Sometimes, new Transformers are simply built from scratch, and that's all it takes. A suitable Transformer body is constructed, and when finished and turned on, it just springs to life. A notable example of this type of reproduction appears in the cartoon: when Wheeljack and company create the Dinobots.

The Dinobots are initially very simple mentally and are ordered to be deactivated because they are too dangerous. Wheeljack then develops a set of crown-like devices to place on the Dinobots which greatly enhances their intellect, although they are still "dumb" and child-like compared to the other Autobots. If one were to take these facts as canonically meaningful (rather than simply the whims of the writers of those episodes), it could be guessed that programming a functional Transformer brain from scratch is extremely difficult, such that even Wheeljack is not up to the job.

At least on the surface, this "built from scratch" approach runs counter to claims in other episodes of the show that Vector Sigma is needed to create new Transformer life. (See below.) However, since Vector Sigma is presented as being a supercomputer and not a "magical" device, it could fall in with the speculative statements above regarding Wheeljack. Perhaps Vector Sigma is simply an advanced enough computer that it is capable of constructing a working mind.

Resurrection
Though not quite the same as reproduction, a copy of the mind or essence of a previously living Transformer may be introduced into a new body and, through some vague process, return that Transformer to life. This occurs when Starscream "creates" the Combaticons in the G1 cartoon.

A variation on this theme is Unicron's ability to create new Robotic life. In the MUX continuity, Unicron creates Cyclonus, Scourge and the Sweeps from the apparently dead remains of unnamed Seekers and Insecticons.

Sexual reproduction
Despite most continuities having male and female genders (gender being a mental and social classification, as opposed to "sexes", a physical distinction) and a definite, strong history of romance existing between these genders, there is little canonical evidence for Transformers reproducing sexually. (Though admittedly, there isn't a lot of direct evidence for humans reproducing sexually in most Transformers media, which is, after all, aimed towards kids.)

Familial relationships
One confusing aspect of this apparent lack of sexual reproduction is the canonical use of genealogical terminology to describe certain relationships. The most common of these is when two Transformers regard each other as siblings: "brothers" (e.g. G1's Sideswipe and Sunstreaker).

Again, the Dreamwave More than Meets the Eye guide provides a partial possible answer. According to the guide, when a spark naturally splits as it's being introduced to a protoform, it creates two robots who are "brothers", such as Sideswipe and Sunstreaker. When such a spark division is artificially induced, the less balanced and less self-reliant pair created is referred to as "clones".

See also: Relatives

MUX Examples
Wheeljack built Snoop as a smaller, faster, more curious Dinobot. She was later rebuilt by Blaster to be a tapebot.

Toys
In the real-life continuity, when two toy manufacturing companies love each other very much, one of them may start shooting Transformer design propositions to the other one. There, during several months of gestation, engineers will work on those designs, which will be developed into functional and manufacturable Transformers. Once the Transformer is ready to be produced, its design will be sent to marketing and ultimately to the chain manufacturer for the delivery. Voilà! A new Transformer is born!