Not yet 4 months old. Hes already about 4 pounds when i lift him. How big will he get? His breed is a Silver Penciled Rock. ( He was supposed to be a female, but obviously someone made a boo-boo. I dont have a roo for my 10 girls and i might keep him(hopefully) hes gentle will let me hold him and sleeps in my arms. We call him big Daddy.