>>718163054
I assume you meant to reply to
>>718161143
In that case: yes, it is a parasite infesting snails making their antenna grow fat and pulsate with that weird scheme. They also abandon their natural behaviour and instead climb up to a high place on a tree/plant. The alleged logic behind it is that the parasite controls and initiates that behaviour, as it is assumed to attract birds which will eat those antenna, which are in fact full of those parasites and this is assumed to be their reproduction cycle step
NTA btw, so maybe the guy that posted the gif has another answer
https://en.wikipedia.org/wiki/Leucochloridium_paradoxum
I didn't read it myself. Just shat out what I remembered, so maybe better rely on that source
