Tons of different types of āslime moldā out there. As far as I know they are not plant pathogens and usually transient when growing on live plants.
Iād physically remove it, but it should not infect the tree.
Crazy! Living in Florida the only slime mold Iāve āseenā has been the shelf fungi that crawl around and eventually build shelves on dead wood to fruit. Iāve never seen the dog vomit in any color!