Any ideas on how they could be added? Behaviour? Drops? Achievements related to them? Are they aligned with anyone? Do they have an ability is some sort? Tameable? Are they based off the Hobbit movie versions, or do they take on a new design?

Questions like this are important to a suggestion, and help to further instigate discussion, which makes the suggestion better still. Short suggestions like this, for things as large as Wereworms, are not advised.

Apologies if this seems in any way rude, for I am not trying to be.

I do not agree with you. Simple or expanded suggestions can be made here. If there is a suggestion that simply has little information, you can always talk about it here and elaborate on the topic.

True, I guess :/

But it really is better to make a full suggestion for things like this. Wereworms have been suggested a few times already. This is less of a suggestion and more of a reminder that Wereworms should be added.