Wet spring/early summer weather can bring out some not so lovely growth in Michigan gardens. One of the most colorfully named of these is “dog vomit fungus” (scientifically speaking that would be Fuligo septicai).
The fungus typically appears as a bright yellow mass on mulch or other decaying wood in the garden. It eventually goes to a brown or tan phase that lasts for the rest of it’s life cycle.
While the fungus is unsightly, it will not harm your plants. It feeds solely on the already decaying matter in your garden beds. So if it shows up in an out of the way spot you can leave it alone if you’d like. But, it is somewhere more visible you might want to scoop it up.
For more information check out this pdf from the University of Arkansas.