The FFG version of Cosmic has always included a subtle marking on 1 destiny card for each color. The rules made clear this was for the Hazard expansion to be released. Hazards are here, as part of Cosmic Conflict, the latest expansion.
However, there are other possible uses for that Hazard icon.
One I'm calling Hazard Aliens works like this:
Each player receives two aliens at start up. One is chosen as their Primary alien, which they reveal at the beginning of the game.
The second alien is the Hazard alien.
Whenever Destiny reveals a Hazard icon, players MAY switch to their Hazard alien. If they do so, it must be during the Destiny phase. At the end of the Resolution phase, players that switched to a Hazard alien must then switch back.
Players must consider that they may not always be a main player during a Hazard encounter. Aliens with Game Setup text should not be used as Hazard aliens. When you switch, your Primary alien is suspended. So, for example, if you are Macron, your ships are now worth only 1; if you are Fungus, the ships in your stack do not add; if you are Filth, everyone needs to watch out for what happens when you switch back.
Other variants for the Hazard symbol destiny cards we've been using so far:
-Offense may draw a card rather than retrieve a ship during regroup.
-Offense draws a Hazard and doesn't reveal it (even if it's his or her second encounter). That Hazard may be played immediately, or on ANY other encounter (even superseding another Hazard).
-Offense draws two Hazards (only if it's a second encounter) and gets to pick which one to play (the other is discarded).
-Only offense may research Tech.
More great ideas are part of this discussion: BoardGameGeek.