What must one do to get this achievement?

I looked up "feed" in the achievements section.

Thank you :)

I believe that is a retired achievement and no longer available to earn the achievement. :( (found under the legacy section)

Thank you! Not all of the retired ones have an indication that they are indeed retired. Very confusing! How do you find out which section it's in if you have searched for it?

They are listed under "Legacy" (Below Seasonal and above Site Events")

Yes - I agree on the "retired status" of achievements. I vaguely remember some discussion years ago about it being unfair for new users not being able to get the legacy achievements.

All the legacy items are so out of anyone's reach today... to make legacy combos costs billions of sP. Unfair all together that I spent years and money on neopets a different site when I could have been doing that here all those years ago! ;)