Like similar moves, stats..
1)All Eeveelution follow a stat distribution of 130-110-95-65-65-60, each one hving a different arrangement.
2)All start off knowing Helping Hand, Tackle and Tail Whip, though Eevee also knows Growl and Sylveon knows Disarming Voice.
3)All are monotypes.
4)All learn Sand-Attack at level 5, Quick Attck at level 13 and Last Resort at level 45.
5)And most obvious, Similar design.