Easter Egg. DotA 6.69 contain a hidden secret which will allow you to fight Icarus the Phoenix. To fight him, you must destroy the PreRune, the Red Runes and then kill all the IceFrogs on the map.
OK, let's start with the PreRune:
After you destroyed, 2 Red Runes will appear on the map.
Continue with the first Red Rune:
After destroy the first Red Rune, 5 IceFrog on the Scourge area will appear. But this time we will go with the second Red Rune first:
After that, you can start killing the IceFrog on the Sentinel area. Let's start hunting! You will need Gem of Truesight (IceFrog is invisible) and Dagon (IceFrog can only be killed with magic damage) before start the hunt.
The above is the example of the IceFrog. It's very tiny and nearly transparent (after the Gem of Truesight). Enable the health bar to make them easier to see. Check out the map below for all the location of the IceFrog:
IceFrog#1 - Near top rune (power up/normal rune) spot on the hill to the hidden shop direction.
IceFrog#2 - Near the Prerune.
IceFrog#3 - Scourge bottom lane. At the spawn point of creeps a bit to the left.
IceFrog#4 - Near the Scourge low level Neutral creeps are.
IceFrog #5 - On the top Scourge camp, near the trees.
IceFrog#6 - Near the spawn point of Sentinel bottom lane. Next to the sea/waterfall.
IceFrog#7 - On the Sentinel's base, on the bottom of the the Hunter's Hall, among the trees.
IceFrog#8 - On the Sentinels middle lane middle leveled Neutral creeps spot. Behind the statue.
IceFrog#9 - Its behind the creeps near the #8.
IceFrog #10 - Near the Sentinel Neutral creeps spot on the bottom lane which nearest to the enemy tower.
After killed all the IceFrogs, suddenly you will be killed and a message appear: "Player has been killed by Phoenix". Well done, if that message appear, the Phoenix is already appear on the boss spot on the top left bottom of the map.