I've been monitoring this for some time and can happily report that Tardigrades (previously at Boing Boing) have finally matched and surpassed the high water mark of popularity that they enjoyed in the 1830s.
According to Google Ngram, the string "tardigrade" appears in 0.0000020291% (20.291 per billion) of its 2019 corpus of English texts. Though just shy of 1835's 20.450 ppb, the trajectory of past years makes it all but inevitable that 2020's Tardigrade tally is even higher, perhaps even 22 ppb.
The tiny yet resilient creatures were first described by the German zoologist Johann August Ephraim Goeze in 1773, who dubbed them "water bears". Lazzaro Spallanzani offered the scientific "Tardigrada" in 1777. The spike in published interest in the late Georgian and early Victorian eras perhaps reflects early scientific interest in cataloging the enormous variety of tardigrades—there are at least 1300 different species—with the technology available at the time.
Interest picks up after the late-1930s development of electron microscopes by Ernst Ruska and Bodo von Borries, slowly growing over the decades until exploding in the mid-late 2010s. For some reason, at this point, audiences became captivated by the idea of invulnerable yet eminently adorable creatures that can go into deep cryptobiotic hibernation for the length of, say, a U.S. presidential term, then be revived with a splash of water to recommence moseying around happily in patches of moss.
Searches for adjacent terms (tardigrada, tardigradum) reveal similar plots, but one is particularly intriguing. Limiting the text corpus to fiction shows a big hump in the 1860s. What was the great Victorian tardigrade novel?