Halo Wars 2

This achievement will likely come naturally while playing online matches as Colony, but it can be done quickly in solo Skirmish matches against the AI on Easy. If you're taking this route, head into the Skirmish lobby and make these setting changes:

• Gametype: Domination
• Starting Supply: 9999
• Starting Power: 9999

Now choose any map and make sure you pick Colony as your leader before initiating the match. Once the match starts, begin building a few Grunt Squads at the Stronghold. At this time, you can use your one Leader Point to unlock the Skitterer in the Leader Powers menu and then begin building a handful of these mobile turrets at the Stronghold.

When the Skitterers arrive on the battlefield, select them with your cursor and then "attach" them to any of the Grunt Squads by tapping over the Infantry Unit. Continue this "attaching" process over and over again as needed throughout the match (or the next match if you decide to quit early rather than wait to upgrade your population count) and the achievement will finally unlock once fifty Skitterers have been attached to a Unit.