xpenguins: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/xpenguins - from package: xpenguins

You may install the required package with command apt-get install {package}

Error in other languages:
xpenguins: bevel nie gevind nie
xpenguins: comandă negăsită
xpenguins: comando não encontrado
xpenguins: commande introuvable
xpenguins: command not found
xpenguins: käsku ei ole
xpenguins: không tìm thấy lệnh
xpenguins: komanda nerasta
xpenguins: Kommando nicht gefunden.
xpenguins: kommandot finns inte
xpenguins: komut yok
xpenguins: nie znaleziono polecenia
xpenguins: níor aimsíodh an t-ordú
xpenguins: no se encontró la orden
xpenguins: no s'ha trobat l'ordre
xpenguins: opdracht niet gevonden
xpenguins: parancs nem található
xpenguins: perintah tidak ditemukan
xpenguins: príkaz nenájdený
xpenguins: příkaz nenalezen
xpenguins: команда не найдена
xpenguins: командата не е открита
xpenguins: 命令找不到
xpenguins: コマンドが見つかりません