Myrmarachne formicaria, a common ant mimic spider around here. They’re actually quite small but I was impressed by this older male specimen I spotted last year.
What I love about finding one in the house is to slowly approach it and see how it transforms its mimic gait (using six of its eight legs to ‘ant-walk’ and two front legs as fake antennae) to a kind of ‘jigs-up’ 8-legged run followed sometimes by a leap into space on an escape thread. On the thread, they look much clumsier than regular spiders. It’s probably the weight distribution to pull off the mimicry.
I was a little suspicious when I first saw this one but walked by it at first before coming back a bit later and realising it was far too symmetrical to actually be a bird dropping https://www.inaturalist.org/observations/231379885
We have a fascinating plant here is New Zealand, Alseuosmia banksii, that regularly fools iNaturalist users as it appears to mimic multiple unrelated and morphologically diverse plant species. There is often much discussion in the comments for iNat observations on this species! This blog post has photos of this species and the plants it mimics: Alseuosmia blog
