What is this?

[ewx]

Found at the bottom of cup of tea, it’s smooth to the touch and fairly bendy. We are mystified.

Comments

[nevboo.livejournal.com]

Slime mold or bacteria. I think they form a pillar like that to produce spores.

[songster.livejournal.com]

Takes a long time to grow to that size though - how long had the mug been left?