I'm wondering if anyone has a guide to collecting avatar items, especially those from the LG. If no one has built one, what are the chances that a big boy boss in TLG drops an avatar item?

I don't know of any guides, but I can give you some general information.

Items that come directly as drops (Malfy squirrels, ent saplings) are really rare. I have all but one squirrel, but I think I bought at least one of the spritelings, and in comparison to the number of times I've beaten bosses... they're quite rare.

Avatar item patterns(? blueprints? I forget), which can be used to craft avatar items through the blacksmith, are more common. I've only actually crafted like 11 things, because of the materials required. But I have a whoooole list of patterns waiting to be crafted. In some cases, I have 3 or 4 of the same pattern. And those patterns can come from elites, too.

Alright, thank you! Guess I just have to keep slicing away at them.