"What did you see?"
A very confused Halloween pennant. Alive, but repeatedly trying to fly toward light. Which here meant ceiling lamps.
I had to lead it, lamp by lamp, to get it to fly back outside.
Then, once it was outside, it kept on trying to fly to the light I forgot to turn off but now couldn't because I didn't want it to fly back in, lol.
Took some gentle forcing to get it to go over the balcony railing.

This is Simon, he’s part of a rescued litter from a feral colony up in Port Hardy that the BC SPCA has in their care. They confirmed by respiratory test that Simon has calicivirus, a lifelong condition in cats that causes coughing and watery eyes when they get stressed. We are fostering Simon and plan to adopt him, so wanted to just iNat his cold, welcome him to the family, and remind everyone reading to keep your cats indoors

Nudibranch Coryphella trilineata (northern form, about 10mm long) & look-alike amphipod Podocerus cristatus. Scanned from a 35 mm slide I took in the lab in 1984. I had found the specimens in close proximity to each other a few days earlier in the low intertidal at Middle Cove, Cape Arago, Oregon. The amphipod (and her recently hatched juveniles, visible at lower right when viewed large) are on a piece of the outer tube of the polychaete Pista elongata; the slug is on a piece of the hydroid Abietinaria.

Notice the white head tentacles of the slug and the white antennae on the amphipod. Here's what one form of the amphipod looks like in central California, where the southern form of O. trilineata ( with chromium orange on their rhinophores and cephalic tentacles) is prevalent: https://www.inaturalist.org/observations/1103734

Farther south, near Puerto Vallarta, MX, the amphipod lacks white lines, just like the abundant local aeolids (see Fig. 1f-h in paper here: https://www.researchgate.net/publication/282252603).