Metamorph Alchemist trades out extracts, bombs etc to be able to Alter Self. starting once per day at first level and getting more later. And later on this can become Monstrous Physique the Giant Form.
Still gets Mutagens and discoveries .
Masked Performer Bard gets a +10 to Disguise rolls for hours using bardic performance .
Arcanists can take the exploit First World Face Theif to gain the benefits of Disguise Self spell by spending arcane resevoir points instead of spell slots.
Skinshaper Druid can turn into humanoid shapes starting at 4th level instead of wildshape.
CloakedWolf Inquisitor gets a bonus on Disguise checks.
Infiltrator INvestigator gets lots of bonuses to Disguises including voices.
Fey TRickster and MAterial Manipulator Mesmerists both start being able to alter their appearance at 3rd level.
Ninjas can take the Sudden Disguise ninja trick.
Occultists have a number of illusion focus powers that let them change appearance.
Oracle with the Intrigue mystery can take Assumed Form revelation and gain Disguise Self at will.
Chameleon and Master of Disguise Rogues for obvious reasons.
Oozemorph Shifter can use Alter Self a number of times per day.
Witches can take a hex that grants Disguise Self.
These are the non spellslot options I can find. There's probably a few Imissed.
