Barkingdog, Lupa doesn't care when Nikki grabs her tail, it's bushy enough I don't think she even feels it. They're always chewing on each other!
They are of course still puppies, but they're just as big as Halo is. They still have that puppy look though, and energy
. In the pic where Lupa and Nikki are on opposite sides of the planter box, you can just make out the black of Halo behind the half dead tree in the box, but you have to know she's there to notice her.