これみたいな感じで http://deeeet.com/writing/2014/04/30/beer-on-terminal/

train_run.rb

csize = `stty size`.scan(/\d+/).map(&:to_i)
puts "\033[2J"
x = 0
Train = "\xf0\x9f\x9a\x83 "
TLength = 10
speed = 1
loop{
    print "\033[2J"
    print "\033[#{csize[0]};#{x}H#{Train*TLength}\033[0;0H"
    x += speed
    speed *= -1 if x <= 0 or x+(Train*TLength).length >= csize[1]
    sleep 0.05
}