Well, I do have a "script" for 19's intro:
"*tile spawns 9
*tile switches to 10 while under 9
*9 moves from over the tile to reveal the '10'
*tile spawns 10
*10 does its beeping thing and then batters the captain (like in 10's intro)
*9 does its lunge across the top bar (like in 9's intro and the entrance to 10's second phase)
*they both go off-screen before coming back
*they orbit around each other before fusing into 19"