Only because I keep looking for it here, and haven't (apparently) posted it yet, here's how to get neofetch to display at boot on various operating systems:
CentOS/openSUSE/SLES: echo "neofetch" >> /etc/profile.d/motd.sh
Ubuntu/Slackware: sudo bash -c $'echo "neofetch" >> /etc/profile.d/neofetch_motd.sh && chmod +x /etc/profile.d/neofetch_motd.sh'
bsd: echo "neofetch" >> /[homedir]/.profile
macOS: echo "neofetch" >> /[homedir]/.zprofile
PhotonOS: sudo bash -c $'echo "neofetch" >> /etc/motdgen.d/01-neofetch.sh && chmod +r /etc/motdgen.d/01-neofetch.sh'
pkg_add neofetch-x.x.x (https://cdn.openbsd.org/pub/OpenBSD)
apt install neofetch
zypper install neofetch
wget https://github.com/dylanaraps/neofetch/archive/master.zip
unzip master.zip
cd neofetch-master
sudo make install
CentOS/openSUSE/SLES: echo "neofetch" >> /etc/profile.d/motd.sh
Ubuntu/Slackware: sudo bash -c $'echo "neofetch" >> /etc/profile.d/neofetch_motd.sh && chmod +x /etc/profile.d/neofetch_motd.sh'
bsd: echo "neofetch" >> /[homedir]/.profile
macOS: echo "neofetch" >> /[homedir]/.zprofile
PhotonOS: sudo bash -c $'echo "neofetch" >> /etc/motdgen.d/01-neofetch.sh && chmod +r /etc/motdgen.d/01-neofetch.sh'
pkg_add neofetch-x.x.x (https://cdn.openbsd.org/pub/OpenBSD)
apt install neofetch
zypper install neofetch
wget https://github.com/dylanaraps/neofetch/archive/master.zip
unzip master.zip
cd neofetch-master
sudo make install