I actually got it not long after my last post ^_^ What I did was just go back and forth, and on my third pet I finally got the achievement. So just rock, paper, scissors, paper, rock, paper, scissors, etc. I'm sure any technique will work too x)

Good luck everyone!

I got all the tiers in one day. c: I had to keep switching pets though because they were getting bored of the game. :c It's hard and I hate the game to begin with, but eh. Good luck to the rest of you. I still think subbie should get the rights for that one 'rock, paper, scissors, lizard, spock' xD

I think the most I won was like 3 times in a row. I sort of want to go back and try it now. =p

I just got it the other day by trying 5 papers in a row. I read in this thread that a few other people got it this way... and it worked!

My usual active pet kept outsmarting me, so one day I got frustrated and started trying my other pets. I got it with the third pet I tried. My system was to always guess my pet's last answer, but it didn't seem to work that well. I wouldn't recommend it.