Today's review of McFarlane Toys' Appa figure discussed the intended size of a sky bison. Here's a shot of Appa and Aang, showing how big they should each be:
And here's a picture of infant Appa, which is closer to the scale McToys has given us:
And as a bonus, here's some early concept art for the series, where the sky bisons' manatee roots are much more apparent:
