Step 1: Visualise a newborn or infant with a small, glistening, deep red knob protruding from the navel that looks just like a raspberry and bleeds when touched.
Step 2: This is mucosa, not skin. It is bowel lining that has prolapsed through a vitellointestinal duct that failed to close completely. The exposed gut mucosa carries the red, berry-like colour and surface.
Step 3: The lesion is named umbilical adenoma. The fact that it is true intestinal mucosa, rather than dull granulation tissue, distinguishes it from an umbilical granuloma.
Step 4: Management is conservative first - a thread is tied around the base so the lesion drops off within days, and any recurrence is removed surgically along with the duct remnant.
\[\boxed{\text{Umbilical adenoma}}\]