Get all the images from http://xkcd.com/1416/

turtles.py

# Get all the images from http://xkcd.com/1416/

import urllib2
import json

ids = []

def process(id):
    if id in ids: return
    ids.append(id)
    data = json.loads(urllib2.urlopen("http://c.xkcd.com/turtle/{}".format(id)).read())
    for id in data.get("white", []):
        process(id)
    for id in data.get("black", []):
        process(id)

process('turtles')
print "\n".join(map(lambda id: "https://sslimgs.xkcd.com/turtledown/{}-tiled".format(id), sorted(ids)))