Might I inquire as to which fonts you used in the example cards for Tumblr Trick or Treat?
You may! The “~USERNAME~ Happy Halloween!” font from the Treat card is “CasualMarkerMF”, and the font for “TRICK” and “TREAT” is “Artistamp Medium”. Both of them are probably free. “tumblr” is just using the site logo and “USERNAME” on the Trick card is my own crappy handwriting.