This season 7 week 7 legendary quest requires you to mark an alien egg.

You have probably ran into alien eggs before this week as they have been in the game for a few weeks already but the amount of alien eggs has been increasing. When you get close to an alien egg it will start to twitch and make a noise then an alien parasite will pop out and attack you.

This quest simply requires you to make an alien egg just like you would mark a weapon or item that is on the ground.

There are plenty of locations that have a consistent spawn of alien eggs. Below is a map showing all the locations. I did this quest at Hydro 16 because there are always alien eggs and it was far from the battle bus route so no other players landed there.

Map credit to fortnite.gg