Huh, I would have sworn that Internet Explorer had the blink tag at one point, but I think my parents had Netscape and then Mozilla pretty early so maybe that's what I'm confusing it with.
Regardless, I stand by my comment. Monsters! I want my browser to be obnoxious.
In theory, in 1996 Netscape and Microsoft agreed to kill <blink> and <marquee> <https://www.w3.org/People/Raggett/book4/ch02.html>, but although they were kept out of the spec, neither removed its implementation, and then IE dominated the browser market, and <marquee> became popular enough that the remaining parties were bullied into shipping it (Netscape in 2002, Presto in 2003, no idea about the KHTML/WebKit timeline), and so ultimately it was put into the HTML Standard.
I think I remember reading articles about how to implement blink in IE using behaviors, some IE only thing that didn't take hold(?), Maybe this was around IE5.
Regardless, I stand by my comment. Monsters! I want my browser to be obnoxious.