I don't even know what section to post this in. Animal, vegetable, mineral, alien?
I found this on the end of a piece of driftwood. It's pretty small, maybe 1/4" for the orange stuff, and 8" or so into the tank so not all that clear in the photo, sorry.
It looks kind of like roots grabbing onto the driftwood, though I'm not 100% sure that those are the same as the orange bulb-y looking things, or an unrelated prior mark (it is 2nd hand driftwood).
It's a new, freshly planted tank, just cycled. Only livestock was introduced in last could days (BN pleco and ramshorns). Only plants are jungle val, crypt wendtii, anubis, and (dying) dwarf hairgrass.
This is the only thing I have seen that looks anything like this. I thought it was artificial at first, but it's not. It is quite orange, perhaps more than this shows.