This looked very like some vomit to me but I was assured there was a bit of it around and it was suggested it might be some kind of fungus.
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
Interestingly, this slime mould is often called "Dog's vomit slime mould"!!
OPAL Community Scientist
Yorkshire and Humber
Lat/Lng: 51.9, -1.1
OS grid ref: SP6531