Yes, you get some more racial spells at both 3rd and 5th level, but I don't think those have been fully implemented yet, one tiefling line has them, the other doesn't yet, most likely the spells haven't actually been added yet.
Cambions are half-devils. Traditionally tieflings have always been, at their very most fiend-blooded, the children of cambions and alufiends (another type of half-fiend). Logically cambions would have as varied a parentage as tieflings do, but they all look the same in most dnd video games, I chalk this up to one part overworked dev and one part "that's what it looks like in the monster manual!".
In 2nd edition your origins were up to you and left vague on purpose, along with having a truly massive roll table for your fiendish features (including wings, and almost anything you could think of). 3/3.5e reigned it in a bit more, but also went with the "distant descendant of evil outsiders" path, which again left it mostly up to the player as to their origin, but still their bottom line was "no two tieflings look alike".
Then 4e came in and basically rewrote tiefling origins to a specific area, kingdom, and group of people. Their basic descriptions also changed. You can read about it in a 2007 publication called Wizards Presents Classes and Races, which was a 4e preview publication and it goes into depth about the tiefling origin. They wanted to standardise the race and make them ethnically similar to each other.
Now, this is where I get a little fuzzy, because I don't keep up with the novel universe. There were two books that came out 2015/16 time, which was a dnd 5e manual, Sword Coast Adventurer's Guide, and a novel, The Devil You Know. These two books rewote tiefling origins AGAIN, basically setting up Asmodeus as the racial god of tieflings, by making all tieflings in the world his direct blood descendants. Yup.
5e tieflings suffered from this decision to make all tieflings the same, but wizards then almost immediately undid that by putting out a whole lineup of tiefling subraces in Mordenkainen's Tome of Foes (which also gave us many elf subraces) because many players didn't like the decision and were ignoring the basic descriptions in the handbook and making whatever they wanted. But larian is sticking to the books in this regard, as much as it pains me.
The planetouched races are my favourite races, can you tell?
Really interesting rundown of the appearance rules from the different editions! I remember running into the problem with the phb that tieflings had to look a certain way but I wanted to make one with antlers. I found some old lore that said they could have more mammal-looking horns aside from ram and was going to roll with it. I never got to play with that character but still want to make a druid tiefling with antlers. Hopefully someone is able to make a mod with more horn variety.
