Height comparison: Smaug vs human

Glaurung, The One Wiki to Rule Them All

What is the most accurate size estimation for Glaurung the dragon? - Quora

The Rings Of Power Could Make Smaug & Shelob Look Pathetic

Ancalagon the Black makes Smaug look like a little baby which just emerged from egg. - 9GAG

Smaug size : r/lotr

Certainly my dragon is bigger - 9GAG

Acnologia vs Ancalagon and Glaurung - Battles - Comic Vine

Dragons The One Wiki to Rule Them All+BreezeWiki

Middle-Earth Comparison, Lord of the Rings vs Hobbit

New mud dragons from Svalbard: three new species of Cristaphyes and the first Arctic species of Pycnophyes (Kinorhyncha: Allomalorhagida: Pycnophyidae) [PeerJ]