Here are a could word ladders to teach the standard and idea that if you change a letter then the word changes. (Standard: There is a simple worksheet for the beginning level, a harder one for the intermediate level and one challenging worksheet. I love using these three differentiated worksheets. You can use them separately over a course of a couple days or for one lesson with students at different levels.
Don't purchase this worksheet and my worksheet titled "Word Ladder" as they are the same, just packaged in different bundles. This download has 3 pages where as the other has only 2.