I bought these plastic animals at an estate sale about a month ago for $1. I'm fairly certain they're from the old Noah's Ark restaurant and bar that used to stand in St. Charles, Missouri. I say this because my parents and grandparents frequented there and would often bring one of these home. The bonus was the little box they came in from Stix, Baer and Fuller, a defunct St. Louis department store.
With their long necks, the giraffes are clearly drink stirrers, but I can't imagine the others were actually placed in a drink as that would certainly pose a choking hazzard. Perhaps some bar afficienado out there can help me identify how they were used.
I'm not sure the mermaids were from Noah's Ark. I'm pretty sure Noah missed those along with the Unicorns when he chose his cargo.
There's an article over on Neatocoolville detailing Noah's Ark's demolition some years back.