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Though this common decomposing fungi is not harmful to your plant, some people and pets are allergic to fungal spores. That fruiting body is how fungi disperse hundreds and thousands (millions?) of spores. I'd remove this mushroom. However, that act will in no way get rid of the actual fungal organism which exists as a network of hyphae and mycelium working hard to decompose your potting soil. NOT a good thing for container grown plants, though good for outdoor soils. I'd think about repotting in new potting medium at some point. Your plant is Schefflera arboricola, by the way.

I am 99% sure you have puffballs. If left alone, they might grow to the size of basketballs, or larger. Or they might only grow to that size. There are many species. All are edible (and prized) when young, although I never tell my kids that any mushrooms are edible, even if I know they are. When they grow older, I can teach them what to eat and what to avoid. When the insides of puffballs turn brown, they are mildly toxic (I think, a strong laxitive). There is a 1% chance they are the very young stage of a regular mushroom, in which case I have no idea what species or toxicity. Here is a link that might be useful: Giant Puffball Mushroom

A search for "Dog Vomit Fungus" or "Slime Mold" should get you more info but it is said to be harmless and only grows on organic matter. Anyway, its scientific name is Fuligo septica.