What is vanilla caviar?

Actually, it is fish eggs, but as an interesting quote says in ZwyerCaviar:

"Caviar definitely is not food. It's a unique product representing many things - an experience, a handiwork, a specialty, a dream perhaps"

Anonymous

Caviar is the processed, salted roe of certain species of fish, most notably the sturgeon (black caviar) and the salmon (red caviar). It is commercially marketed worldwide as a delicacy and is eaten as a garnish or a spread; for example, with hors d'œuvres.

Eggs Of Sturgeons