Absolutely JavaScript, in that it is easy to accidentally do horrifying things, but absolutely not surprising if you’ve spent any time working with it, as you quickly get used to how awful it is.
I’ve been in some sort of web development since 2005 and am to this day surprised by just how much awful is packed in there. Most is deprecated - thank God and any other deities - but it’s still there lurking for newbies and unaware developers coming from sane languages.
Have you seen how people can write JavaScript within CSS yet? That's another fun one. :)