Changing a fox to a hen:

fox, fax, fan, ran, ban, pan, pen, hen
fox, fog, bog, dog, dig, din, den, hen

Changing a cup into a ship:

cup, pup, pop, top, tap, lap, flap, flip, lip, sip, ship

Getting a dog to pull a sled:
dog, hog, hot, lot, not, net, Ned, fed, Ted, sled 

Some challenging changes:

lean, bean, been, bees, bets, buts, cuts

join, coin, coil, toil toll, tell, well, weld