blink frame easteregg aside 
Answer: Blink
In the late 1990s, long before the advent of annoying flash advertisements, pop-overs, and other irritating web browsing experiences, there was blinking text; no other HTML design element has enjoyed more focused hatred than the tag.
What’s deeply amusing (or unfortunate depending on who you ask) is that the scourge that is the blink tag came into existence entirely as a silly browser Easter Egg conceived after a night of drinking. Louis Montulli, an early and influential web browser programmer, explains the origin of the blink tag on his personal web site:
Sometime in late summer I took a break with some of the other engineers and went to a local bar on Castro street in Mountain View. The bar was the St. James Infirmary and it had a 30 foot wonder woman statue inside among other interesting things. At some point in the evening I mentioned that it was sad that Lynx was not going to be able to display many of the HTML extensions that we were proposing, I also pointed out that the only text style that Lynx could exploit given its environment was blinking text. We had a pretty good laugh at the thought of blinking text, and talked about blinking this and that and how absurd the whole thing would be. The evening progressed pretty normally from there, with a fair amount more drinking and me meeting the girl who would later become my first wife.
Saturday morning rolled around and I headed into the office only to find what else but, blinking text. It was on the screen blinking in all its glory, and in the browser. How could this be, you might ask? It turns out that one of the engineers liked my idea so much that he left the bar sometime past midnight, returned to the office and implemented the blink tag overnight. He was still there in the morning and quite proud of it.
The tag was intended to be a joke, something arcane that programmers would stumble across, laugh at how annoying it was, and move on. Unfortunately, once the blink tag was in the wild, it ran rampant on high schoolers’ personal web pages and corporate splash pages alike.