Bill Cipher

17-23-11-19 15-5 9-2-19-6, 23-10-20 15 1-9-10. 10-9-1 15-4'5 4-15-11-19 4-9 5-4-23-6-4 4-16-19 18-3-10. 15  23-12-1-23-25-5 12-9-2-19 21-9-6-6-3-8-4-15-10-17 12-15-2-19-5. 10-9-1 12-19-4'5 5-19-19 1-16-15-21-16 8-15-10-19-5 5-3-6-2-15-2-19-5.

I just love Gravity Falls! This show is so great. And Bill Cipher is neat.
You can also watch process of drawing at YouTube
Hope you like it!