#1
When Gravity Falls, Call a Phantomby Destiny
Gravity Falls x Danny Phantom (side series to my 'Mutants' series) Happens after book three and before book four.
Danny and his family go on a vacation, along with Saman...
#2
Gravity Fallsby Sally
Dipper and Mabel come back to gravity falls, but they find something they thought they had defeated.
#3
Gravity falls texts by gooseberryplum
Just a bit random really.
May contain swear and other naughty things so you have been warned.