According to BS01, the singular of Parakrekks is Parakrekks, and the singular of Protocairns is Protocairn. (Both are combiners from 2005.) That seems to make sense since Parakrekks seems like a Matoran word, but Protocairn seems more like an English word. However, the editors realized that the encyclopedias only refer to the Protocairns and Parakrekks in the plural. (Apparently Comic 23's centerfold alludes to a singular "Protocairn," but it was pointed out that this may be an error.) Could you clear up the singular forms of those words?
Thanks for the answer and for keeping in touch with the fans!