The gallery of intervals' pictures:
Perfect unison
Minor 2nd
Major 2nd
Minor 3rd
Major 3rd
Perfect 4th
Tritone
Perfect 5th
Minor 6th
Major 6th
Minor 7th
Major 7th
Perfect octave
Minor 9th
Major 9th
Minor 10th
Major 10th
Perfect 11th
Perfect 12th
Minor 13th
Major 13th
Minor 14th
Major 14th
Perfect 15th