How do you say tadpole in Slovak?

I've recently seen a newspaper ad for a Slovak course for Czech speakers. As the two languages are extremely close, I doubt that many Czechs are interested in studying Slovak. Anyway, the ad asked about a word that is usually not known to Czechs. Jak se říká slovensky pulec? (How do you say tadpole in Slovak?) Three options were given: puliec, žubriä and žubrienka. Neither puliec nor žubriä exists, the correct answer is žubrienka (which can also refer to a child). Now, if I were a Czech who would like to speak Slovak, pulec (tadpole) would not be on my list of priorities of words to know, as how many times in your lifetime do you have to refer to it? I would have chosen a more practical word that would befuddle Czechs, such as Jak se říká slovensky inkoust? (How do you say ink in Slovak?) The answer, by the way, is atrament (also found in Polish, from Latin atramentum).