They could have just dragged it along the pond until it caught. lots of spiky bits on dragons to catch on. It may have taken a while.

You know what’s driving me crazy though? Look, I’ll give it to the Walkers that they got their hands on those chains. It’s a stretch but they’re an army of thousands; the concept that they have access to heavy equipment is actually kind of interesting. But what makes no sense is how they hooked the chains up to the…