Gage Creed (first appeared in Pet Sematary)

The main character's son, who is killed and then brought back to life in the burial ground.

Gage Creed is mentioned in the following books:

Insomnia (Sep 1994)

Gage's shoe is discovered in Atropos' lair.

Here was the buck knife of a man who had been killed in a hunting accident in 1937. Here was the compass of a Boy Scout who had fallen and broken his neck while hiking on Mount Katahdin. The sneaker of a little boy named Gage Creed, run down by a speeding tanker-truck on Route 15 in Ludlow.
- Part 3 / Chapter 25

The Dark Tower IV: Wizard and Glass (Nov 1997)

One of the streets in Topeka seems to be named after a certain little boy...

All Amtrak rail travel has been suspended, not just in Topeka but across all of Kansas. The Gage Boulevard Amtrak station has been closed until further notice.
- Part 1 / Chapter IV: Topeka