Cowsay GUI is a free and open source ASCII art generator with a message for Linux. It is based on old Cowsay app by Tony Monroe but with complete rewrite using Vala and the GTK. It is released under GPLv3 license. It comes with a variety of templates like different types of cow, dragon, elephant, tux, turkey, snowman, sheep, koala, duck and many more.
How to Install Cowsay GUI on Ubuntu Linux
Cowsay is available as a flatpak package file from remote flathub. So first install flatpak and flathub on your system and restart it after the installation.
Open the terminal software using the ctrl+alt+t keys or via the applications menu. Now in the terminal app run below commands.
flatpak install flathub org.gnome.gitlab.Cowsay
It will install the latest version of Cowsay app on your system. Now after the installation you can open it using this command.
flatpak run org.gnome.gitlab.Cowsay
And uninstall it using
sudo flatpak uninstall org.gnome.gitlab.Cowsay