@Boulder318  
They can stand on clouds like pegasi.

@Stotter  
Griffins aren’t canon magical.

@Boulder318  
They’re magical creatures with bird and cat traits, not hybrids of non-magical birds and cats.  
Yaks aren’t magical, so they lack a workaround.

@Stotter  
I say again, griffins - birds and cats, also not in real life.

@Boulder318
 
@Background Pony Number 17  
Assuming that tree of life on Fluttershy’s chalkboard was accurate, and that the separate origins of life were for magical and non-magical creatures, then hybridization, while potentially being easier for different magical species, is just as impossible for yaks with magical ponies as it would be with horses in real life.
 
Of course, we don’t ship based on ability to reproduce, not even in real life. Her being considered a calf until last Yikslurfest is much more the issue here.

@Stotter  
Don’t be speciesist.

It must suck having to read everything on the ground.

“Pony give Yona scribbly toilet paper?”

@Stotter  
…and yet we have griffins and hippogriffs….

I don’t think he wants to read your love fanfic between you and him, Yona

@genervt  
This really made the episode, yes. Such a cool yak gal.

@toonbat
 
Yes XD

Something of note with this ship, Yaks are bovids. They hybridize with bovines, not equines.

Humanized Rockhoof and Yona classroom scene: