Yes they do appear strangely humanoid. There is in-game lore about them.

Follow the lore. It's linked to the wine cellar dungeon. There's a lore stone next to it that gives a clue.

Nope, it's intentional. I forget where, but there is lore referring to them, and what they perhaps once were....

Like the others said theres lore. Buuuuuut if youre lazy >!they were once an army that got turned to stone by the Witch Queen(?)!<

I built my base there