This is a 12 gallon that cycled for a month and has an assassin snail/lots of bladder snails, plus 2 guppies that I added 6 days ago (there was a 3rd, but he jumped out of the tank a few hours after I got them after lots of erratic swimming). However, the remaining 2 have been swimming and eating with gusto (though I have been careful not to overfeed for fear of ammonia spike) and appeared pretty “normal” to me for the first 5 days. I noticed one of the guppies had some scale discoloration yesterday, but they both ate before I left for work early this morning ~14 hrs ago and I left the light off because I figured the discoloration was stress related…I just got home, turned on the light to take a look at them, and discovered 1) both of them look undeniably sick with what appears to me to be fin rot and/or possibly something fungal and 2) this creature(?) is here. I’m honestly kindof freaked out.

I’m testing parameters right now and I’ll comment below, temp is about 74f.

And, um, who is this guy?