So, remember when Pinkie Pie visited bill house in the previous inktober ?  
Pinkie Pie got the S.S.Anne ship ticket.  
So, she wanted to check out the ship.  
While in the ship, Pinkie Pie met the poor captain who got seasick.  
So, because Pinkie Pie felt sorry for the captain, she and charmeleon try to make the captain feel better.  
After that, the captain wanted to show Pinkie Pie and Charmeleon about a Hidden Move 01 but then because the captain still not in good condition, he gave the HM 01 to Pinkie Pie.  
And that’s how Equestr-I mean Pokemo-I-I mean Pinkie Pie got the HM 01, cut.
 
Update: I wanted to make inktober works as a portfolio, so I change to a more proper illustration.