This pattern is sized off my small calf that also fits my Nigerian dwarf goats but it gives notes on how to adjust sizing.
You will need:
one skein for ww#4 yarn (i used red heart)
h (5mm) hook
button (i used 16mm)
scissors
tapestry needle

basic stitches to know:
st
ch
sc2tog
hdc
hdc2tog
dc