(maybe not very interesting actually, but quite fascinating to me)
Never was a fan of toys or cartoons or other comics, but IDW 'More than Meets the Eye' and 'Lost Light' arcs were interesting readings, despite the universe and many story elements making little sense. One of the things that strikes me as very interesting, is Transformers themselves and their, for the lack of the better word, mecho-biology.
In DnD constructs are mostly understandable. Broadly they are either clockwork reminiscent of clockwork toys and mechanisms, golems close to elementals (solidly built in the single material, be it tar, or flesh, or stone, thanks to their origin in Golem of Prague as a pile of clay), or magical esoteric-circuits robots, close to what is possible near-now, with magic used to fill the gaps in not-yet-existing technology. Crystals often serve as their power sources but don't carry any other functions even in sapient constructs.
Transformers are mostly close to the third, but I think their initial out-of-universe nature of the toys serves like a coherence glue or a boundary in terms of what 'magic' is for them in-universe. What exactly are the possibilities and limitations will depend on writers for each universe, but within a single canon it can be made more or less consistent.
– Transformation cog, which is in this continuity, is the 'organ' responsible for transforming. The shape and capabilities of alt-modes themselves are more embedded in the actual body, but transformation cog is what makes the transformations possible. Every Cybertronian is forged or constructed with one: it takes intent, disease or accident to disable this ability, and often the rapid destruction of the cog is fatal. Imagine the whole sapient population of the planet be able to shift into something else, and this can be tangibly taken away and returned back.
– The spark, which can be compared to combination of soul, heart and main engine; it is vague if the spark also at least partially encodes personality but I am inclined to say yes. The origin of spark in incomprehensible super-computer inside of Cybertron makes it alike to soul, but, unlike intangible and vague soul, the spark is condensed, materially present and very obvious source of energy with a lot of known properties. In comics it usually takes a dedicated medic or a scientist (often unhinged one, such as Scorponok) to do truly unusual things with the spark, but all Transformers have some basic intuitive understanding and use of the spark as of energy source or/and are able to detect 'spark signature' from a distance. Imagine the whole sapient population have a instinctive basic understanding of soulcraft.
– Energon, the fuel, catch-all 'food' but also a 'blood' within transformers: they consume it as nourishment or for pleasure, and transport it as goods, but it also flows within them and splatters on drastic wounds, as the blood would. It is mined from the rocks, so it can be said that rocks on the planet bear raw coagulated blood-equivalent. Aesthetically, it is mostly portrayed as extremely bright magenta which makes me think that pink colour of Arcee and the deep purple of Decepticons in our terms would be bright scarlet of arterial blood and carmine of venous blood respectfully.
– Metal of the bodies is one thing that doesn't seem to be lacking in usual circumstances (an average Transformer is about 30 feet tall and 16 tons heavy of mostly metal), but in a pinch the population can be melted down and recycled to mass produce more of something else, be it mindless Legislators of Tyrell, or new soldier Cybertronians in a Functionist universe, or just more guns. It is barbaric, but not terribly difficult thing to do technically. Imagine the whole population that potentially could be dissolved and reformed into something else, sapient or not.
– Body modifications: it isn't too difficult in-universe to change their bodies, providing materials, tools and specialist's attention: Traincutter got guns into his legs, Perceptor upgraded himself as a sniper, and some Transformers rebuilt their whole form several times. Transformers are somewhat limited, in-universe, in how much of mass each can bear naturally but there are ways to bypass it with mass-displacement.
A lot of such modifications are also immediately obvious, so if Transformer has change in appearance it is most often means they also got the change in their capabilities. It makes me wonder why, in-universe, free of limitation of the toys, Transformers don't do it more often and seem to rely more
on other Transformers who can help them (the portable telecom station you use to detect enemies is your buddy Radar, you shoot sniper rifle who is also Vox) than to add more gadgets to/into
themselves. In some ways, their technology doesn't seem to think about minimization and optimization because there is probably a 'bot somewhere who already have this kind of talent. In human terms it can be imagined as if at least half of spells, feats and skills be immediately obvious on the character, leaving much less space for subtlety or disguise.
Additionally, careful removal of many secondary parts is not immediately life-threatening even if harmful on longer run; some medics or scientists can disassemble others almost entirely and reassemble them back without much problems. You can have a calm, not time-stressed conversation with somebody who is, basically, has your stomach in their hands, and it causes concern only if they won't give it back.
– Various bodyparts, which are simultaneously organs, tools and parts of appearance. Taking somebody's feet could be seen as taking somebody's boots, taking somebody's roller blades and taking somebody's actual feet to replace one's own. It is mostly tied to the body modifications above, but also to notice that Transformer's look clothed to us while they actually aren't, and they don't have a separation of body into basic and clothed forms, and have their more or less permanent looks as a part of their full identity.
Given what their bodies are, there are many more things possible to do with them than with biological bodies, and even Transformers who aren't specializing in medicine, mechanics or science can probably re-engineer a dead body or a bunch of organs into something else intuitively; medic or scientist with better understanding can do this on a go or more drastically, such as making a corpse without any weapons itself into a gun. Intact corpses can be used in their alt-modes as a strange form of mechanical necromancy by pretty much anybody on a go.
– The lack of separation between the body and appearance also creates this very unusual scarcity of personal belongings
comparatively to humans and their need of many soft things. Occasionally there is a ceremonial cloak or a hat, but often tools or weapons are either the part of Transformer themselves, or directly attached to them. One of the most valuable personal-access things in-universe are good labs; on smaller scale personal unattached belongings often limited to datapads and various collectables. The dwellings of Transformers look very austere, and this detachment also makes Transformers look very mobile and non-possessive. It makes me wonder if they even have emotional understanding of 'home' as of place in the way we do. Transformers arts also seem to gravitate toward ones that don't need extra tools or materials: there are songs, poetry, performance, but little of painted pictures, sculptures or mosaics; Transformers seem to carry their art with them wherever they go.
– Transformers themselves vary drastically in the size, from somebody as small as Rewind to somebody as big as Ultra Magnus (and there are Omega Supreme and the Titans who are the size of the cities although not very personable). Appearance/looks alone seems to rarely matter to them: mouthplate or actual expressions, actual eyes or a visor, and whatever colours, are all treated more or less the same. In these particular comics there are themes of discrimination on other principles than appearance, and sometimes appearance is tied to one's capabilities (which could be disparaged) but I am finding it remarkable that the appearance itself is very rarely a problem.
– Age, which easily stretches for millions of years and only having an health-related or psychological effect when the plot (usually sickness) or characterization (usually gruffness) demands it. Otherwise Transformers don't seem to process the span of time, being functionally almost immortal, and stop changing psychologically once they establish their personality (which might be as soon as a two weeks from creation). They are not lethargic, they don't have 'the long view' and they live day-to-day as fast as a human would, but being aware of the full scope of time is an exception to them. To add, that their often-metal world, seems to be similarly unaffected by the time: ships and structures exist for millions of years without decay or rust.
With all of this, I think the nearest fantasy equivalent of Transformers would be not constructs but Fair Folk, with their Seelie (nominally benevolent Autobots) and Unseelie (Decepticons) Courts, shapeshifting, eldritch blood, basic immortality, much better understanding of their own 'magic' and having some basic intuitive skills and senses beyond human ones, variable appearances, condensed tangible spark different from how humans understand soul, and bizarre but still recognizable and not fully alien forms.