1. A horn results when glaciers erode three or more arêtes, usually forming a sharp-edged peak

https://nsidc.org/cryosphere/glaciers/gallery/aretes.html

2. A pyramidal peak, sometimes called a glacial horn in extreme cases, is an angular, sharply pointed mountain peak which results from the cirque erosion due to multiple glaciers diverging from a central point. Pyramidal peaks are often examples of nunataks

https://en.wikipedia.org/wiki/Pyramidal_peak

By Photo: chil, on Camptocamp.orgDerivative work:Zacharie Grossen - Camptocamp.org, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16791896