User blog comment:OVERPOWERED99/Dragonpedia Size Images are confusing/@comment-5690373-20150125201757

The HTTYD 2 TCG has the length, weight and wingspan of many dragons. This site has scans of most of those cards.

http://www.tradingcarddb.com/ViewAllSet.cfm/sid/97021/2014-Topps-How-to-Train-Your-Dragon-2

Unluckily those images are hard to read. As for the measurements, some are calculated from game models relative size. It could also be made up, which unfortunately happens a lot.