Not 100% sure. Fairly new to slime molds, but this looks like a good fit.
About 1" long, on oak log. Looked just like a nudibranch :-)
on Eucalyptus botryoides
Two large white masses at the top of a dead Monterey pine tree in an open space at the top of Valley Steps which match the descriptions of Enteridium lycoperdon. This morning, one had burst and showed they cocoa powder-like insides mostly blown away leaving the spore print. Another large mass had formed below the first two. The sizes were about 8-10 inches square.
For more than a year, I have noticed small buttons of similar masses scattered over the trunk.
Two more masses have appeared, dried out and broken open to expose the mass of brown spores. The third was larger and drooped from the weight. The fourth was smaller and about 3-4 inches across and about 5 inches down as it drooped from the weight.