TIL about quilt headers. Looks like this one matches all the other cows:
Description: add a fox 'cow'
Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=888229#5
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=888229
--- /dev/null
+++ b/cows/fox.cow
@@ -0,0 +1,18 @@
+$the_cow = <<EOC;
+ $thoughts ,-. .-,
+ $thoughts |-.\\ __ /.-|
+ $thoughts \\ ` ` /
+ /_ _ \\
+ < _`q p _ >
+ <.._=/ \\=_. >
+ {`\\()/`}`\\
+ { } \\
+ |{ } \\
+ \\ '--' .- \\
+ |- / \\
+ | | | | | ;
+ | | |.;.,..__ |
+ .-"";` `|
+ / | /
+ `-../____,..---'`
+EOC
--- a/debian/copyright
+++ b/debian/copyright
@@ -31,6 +31,10 @@
Copyright: 1999 Geordan Rosario <geor...@csua.berkeley.edu>
License: COWSAY
+Files: cows/fox.cow
+Copyright: 2019 Hansen Wu <hansen.wu...@gmail.com>
+License: COWSAY
+
Files: cows/gnu.cow cows/suse.cow
Copyright: 2006 Gerfried Fuchs <rho...@deb.at>
License: WTFPL-2
