Add some. And try to have fun!
  1. Hound in houndstooth
  2. Soy in Soylent Green
  3. Mice in mouse pads
  4. Teeth in Bluetooth
  5. Thunder in Thunderbolt Displays
  6. Apples in Macintosh computers
  7. Stop signs in stopwatches
  8. Holes in the holy bible
    Unless you shoot at it with a bullet gun or paper hole punch it but don't cuz blasphemy
  9. Babies in baby teeth
  10. Blow in a blowjob
  11. Elephants in elephants in the room
  12. Fruit in fruit rollups
  13. Phones in microphones
  14. Carp in carpal tunnel
  15. Dents in the President
  16. Dogs in hot dogs
    We hope
  17. Rafts in drafts
  18. Feet in footballs
  19. Dogs in dogfish
  20. Bars in bark
  21. Kin in kindness
  22. Ass in class
    Suggested by @aedan
  23. Bullets in a Nutribullet
    Suggested by @eliolsberg
  24. Shit in a shitstorm
  25. Sand in sandwiches!
    Suggested by @nikkiwerner
  26. Doctors (or peppers) in Dr. Pepper
    Suggested by @rianhandler
  27. Crack in crackers
    Suggested by @TheAnne
  28. Butt in butter
    Suggested by @Chip