Request for Feedback: Cow Go Moo

Curious for a bit of feedback for this design I'm drawing. It's a cow standing around... Going moo.

Anyway, what I'm unsure about most of all is if it should just be the cow by his lonesome:


Or if I should have him saying "Moo!" (which is always the way I've drawn him on paper):


Or if there should also be a little bit of grass underneath him:


In addition, if the "Moo!" text is preserved, what color should the letters and the bubble be filled with?

Thanks in advance for your input!