Big Foot Slippers were designed for my dear hubby. Other shoe sizes are easy to find in slipper patterns, but I could never find a size either big enough or sturdy enough for his 6'5.5" frame.
He absolutely loves these and has them on all the time when he's at home. I've made a pair of these for him each year for about 8 years now, have adapted the pattern for a size 11 and even made a smaller version for myself.
Round 1 - ch 6, join with sl st into ring, ch 3, 14 dc in ring.
Depending on your gauge, you may need to start with 12 dc instead of 14. After the third or fourth row, do a "test wear" to make sure they're the correct size.
If you want a smaller slipper size, dec the amount of DC you start with. I've gone down to a size 6-8 by starting with ch 4, dc 10.
Round 2 - ch 3, 1 dc in join (1 dc, 2 dc around), join with sl st
Round 3 to 8 - ch 3, dc around, join with sl st
For a shorter slipper, subtract rows here.
Round 9 to 14 - ch 3, dc around, don't join, ch 3 turn (do not ch 3 turn last round).