We all have those nights where either we are too sick to write plans or worse, our children are sick and need our attention. I have created a full day (which is actually more like 2 days of material, realistically) of plans centered around the book Diary of a Worm (which is available on Youtube in case you do not have a copy). The plans include 4 reading, 1 writing, 3 science, 3 math, and 2 social studies activities. They are all fun and engaging for students and cover many different topics. One of the math pages has a choice of medium or advanced difficulty, depending on your grade level.
Also see my other emergency sub plans:
The Lorax: http://www.teacherspayteachers.com/Product/Emergency-Substitute-Plans-for-Grades-2-4-Using-The-Lorax-1146990
Scaredy Squirrel: http://www.teacherspayteachers.com/Product/Emergency-Substitute-Plans-for-2nd-4th-Grade-Scaredy-Squirrel-713217