Eric E. Koster, age 56, of Shawano, passed away on Monday, October 12, 2026, at his home. Eric was born on July 1, 1970, in Aurora, Colorado, the son of Edith V. (Frechette) Koster and the late Herman J. Koster. He was a graduate of Gresham High School class of 1989. Eric served his country proudly in the United States Marines Corps and was honorably discharged. He lived in Black River Falls, Wisconsin for a while before moving back to Shawano County, where he lived most of his life. Eric worked in security for the Menominee Tribe and various other entities. He attended church in Morgan Siding. Eric loved to fish, was an avid L.A. Dodgers and Chicago Bears fan and was an animal lover. His dog, Neo was his forever sidekick. He was a great story teller, impressionist and had a wide variety of vast knowledge. Music was a passion; he could name any song, band, artist that came on the radio.

Eric is survived by his children, Zamantha Funmaker-Koster and Dominic Koster; stepdaughter, Olivia Pyawasay; partner, Rochelle Tourtillott; mother, Edith Koster; siblings, Joan (Jon) Latham, Dawn Koster and Herman Koster; nephew, Aric Koster; and niece, Sarah Lindsey. He is further survived by many aunts, other relatives and friends.

Eric is preceded in death by his son, Isaac Bryan and father, Herman Koster.

A memorial service will be held at 1:00 pm on Sunday, October 18, 2026, at Swedberg Funeral Home in Shawano. Visitation will be held at the funeral home on Sunday from 11:00 am until the time of service. Military honors will be conducted by the Keshena American Legion at the funeral home following the service. Memorial donations can be sent to Shawano Humane Society in Eric’s memory.