in the absence of a trunk or stone to lean on, a capybara may be an option;
I have observed these two individuals do this twice;
see also
https://www.inaturalist.org/journal/nelson_wisnik/21258-the-friendly-capybara
Found by Charles Paxton in Lincoln Parish Park, Ruston, LA. Growing on decayed deciduous log near a creek in mixed deciduous/pine forest. Photo 5 showing bacciliform spores in Melzer's; photo 6 & 7 microscopic features including ascus.