The forgotten roost drops manticore eggs & dragon eggs on rare occasions. Have you not gotten either one yet?
Check your forge occasionally since I had a manti egg drop sometime over the last few days since I saw it there without realizing it had dropped. I wouldn't recommend buying either of those.
Maybe the fortune teller tent would give you mini-goals every few days and once you get sinister, sister you'll need that old log fortune. It really helps.