The defensive end is currently projected as a first-round pick by many.
"I've been wanting to do that my whole life. I love you, mom."
Shelton is the second Penn State defensive lineman to enter the transfer portal Wednesday, joining Judge Culpepper.
Culpepper made five total tackles and a 0.5 sack this past season.
Shaka Toney was Penn State's lone first-team selection, but four other Nittany Lions got the nod to the second-team.
Chris Godwin scored the lone touchdown among Nittany Lions in the NFL this week.