The Redcap described in Volo's Guide to Monsters is a chaotic evil fey that looks like a demonic garden gnome. They have a strange property – they burst out of the ground wearing heavy iron boots. They are described in VGtM thus:
The creature has a pointed leather cap, pants of similar material, heavy iron boots, and a heavy bladed weapon. From the moment it awakens, a redcap desires only murder and carnage, and it sets out to satisfy these cravings.
Redcaps lack subtlety. They live for direct confrontation and the mayhem of mortal combat. Even if a redcap wanted to be stealthy, its iron boots force it to take ponderous, thunderous steps. When a redcap is near to potential prey, though, it can close the distance quickly and get in a vicious swing of its weapon before the target can react.
Because of these boots, the statblock for the Redcap lists this interesting feature:
Iron Boots. While moving, the redcap has disadvantage on Dexterity (Stealth) checks.
Why doesn't a redcap just…take his boots off? Are his boots actually just his feet? Is subtlety just so far removed from his nature that even with his 10 intelligence he doesn't think that maybe barreling through the forest like a tiny freight train isn't the only option?
Is there any official source material (Fifth Edition preferred) that explains the lore surrounding a redcap and his boots?
Best Answer
They could take off their boots, but they don't
Redcaps are based on older myths from England, and in all of them they wear iron boots. D&D simply copied that part of the lore in and then attached some rules to it.
Wikpedia:
Mythology wikia:
Villains wikia:
None of these sources suggest anything about the boots being part of their body, they're just boots. However the creatures don't have an origin story in any of these myths. D&D made one and apparently it involves them just appearing with their full gear (they are also born with their magical red caps, as well as their scythes) but that's probably mostly because it's the easiest way to explain how this whole "you need to soak this thing in blood every 3 days" works without having to come up with a way for them to make the cap. (And why would they do that then, anyway?)
So yeah, they could take off their boots. But they don't. Probably because the boots are useful to them (enabling their sprint-kick power, which makes them considerably more dangerous and creates more carnage, which they like).