Talk:Achievements/@comment-27719960-20160202055755/@comment-27741705-20160205222405

You need to have all 10 of them in the same area.

If you have 8 in the Grotto and 2 in the Overgrowth for example, you won't get the achievement.

Put the 2 largos that are in the Overgrowth with the 8 in the Grotto and you'll have 10 largos in one place, granding you the achievement.

If this doesn't work for you however, then I don't know what else to do since these are the requierments for the achievement.