Thanks - I'll run an update pass on the models later. The models are pulled from Bedrock Edition, not Java, and often times there's minor differences like this one. It probably got fixed in an update and I just haven't pulled those changes in yet.
You can pose any model that has bones set up correctly; you just have to click and drag on the pieces individually. There used to be a way to switch between bones but I think it got lost in a style update, I'll see about getting that back in.
Axolotl rear legs are shown in the wrong location