Aliasing digigrade → digitigrade
Link to alias

Reason:

common misspelling

Yep.
Maybe also alias digitgrade, digitrade and ditigrade. And there's a lot of less common ones too: https://e621.net/tag?name=di*grade&type=&order=count&show_empty_tags=1

I had a feeling that tag would be like this. Yeah, approved I'll go through these now.

Edit: I did the likely ones that I saw and left the typing errors (e.g., dififigrade) as is. If there are any more likely ones, feel free to mention them.