odd question

[stones2409]

Don't know what to put for this question?
'What are made when drawing for the Simpsons'

Thanks for any ideas

[Ternigapp]

Bit of a long shot but how about the letters M & G

When Matt Groening originally drew Homer he put his initials into the character's hairline and ear (M in the hairline and the right ear resembles G) so not sure if he incorporates the letters into all the characters.