User blog comment:Httyd big fan/Seventeenth Dragon Fight Club Match: Timberjack vs. Typhoomerang/@comment-24126950-20180404031440/@comment-24413325-20180405075817

It isn't outright stated anywhere, but every source (other than the Dragonpedia) implies that the Timberjack is longer and has bigger wings. For example, the Guide to The Dragons says Typhoomerangs are 35 ft long with 50 ft wingspan, while Timberjacks are 60 ft long with 90 ft wingspan. Said sizes are smaller than they actually should be, but the guide still implies Timberjacks are larger.