Linux figlet fonts path:
cd /usr/share/figlet
Mac OS X figlet fonts path (installed with homebrew):
cd usr/local/Cellar/figlet/2.2.5/share/figlet/fonts
Show all figlet fonts with preview:
showfigfonts "hello world"
Use a certain font:
echo "hello world" | figlet -f "ANSI Shadow"
List of more figlet fonts: