A (Mostly) Complete List of Ways to Obtain Creature Companions in Pathfinder First Edition:
(Sourced from this thread: https://paizo.com/threads/rzs2pjan?Ways-to-gain-a-Familiar-or-Animal-Companion)
Animal Companion/Mount options: • Barbarian: Mounted Fury (5th; bestial mount; -4; APG) • Barbarian: Mad Dog (1st; war beast; Animal Archive) • Cleric (4th; animal domain; -3) • Druid (4th; nature bond: animal domain; -3) • Druid (1st; nature bond: animal companion) • Druid: Treesinger (1st; plant bond: plant companion; ARG) • Druid: Pack Lord (1st; animal companion; UM) • Paladin (5th; divine bond: steed) • Ranger (4th; hunter's bond: animal companion; -3) • Ranger: Beast Master (4th; animal companion; -3 until 12th; APG) • Sorcerer: Wildblooded (4th; sylvan bloodline: animal companion; -3; UM)
• Cavalier (1st; mount; APG) • Cavalier: Beast Rider (1st; exotic mount; UC) • Cavalier: Huntmaster (1st; hunting pack; Animal Archive) • Inquisitor (4th; animal domain; -3; APG) • Oracle (1st; nature mystery: bonded mount; APG) • Samurai (1st; mount; UC)
Familiar options: • Bard: Sea Singer (2nd; familiar; APG) • Cleric: Demonic Apostle (drow; 1st; demonic familiar; ARG) • Cleric: Fiendish Vessel (tiefling; 3rd; fiendish familiar; ARG) • Druid: Blight Druid (1st; nature bond: familiar; APG) • Druid (1st; eagle domain; UM) • Druid (1st; toad domain; UM) • Druid (1st; monkey domain; UM) • Druid (1st; serpent domain; UM) • Rogue (10th; advanced rogue talent: familiar; -4; UC) • Rogue: Carnivalist (1st; familiar; Animal Archive) • Sorcerer (1st; arcane bloodline: familiar) • Sorcerer (3rd; serpentine bloodline: serpentfriend; -2; APG) • Wizard (1st; arcane bond: familiar)
• Alchemist (2nd; discovery: tumor familiar; UM) • Gunslinger: Buccaneer (human; 1st; exotic pet; 1/2; ARG) • Magus (3rd; magus arcana: familiar; UM) • Ninja (10th; master trick: advanced rogue talent: familiar; -4; UC) • Witch (1st; witch's familiar; APG) • Witch: Beast-Bonded (4th; enhanced familiar: +1 to effective witch level; UM)
Other: • Anti-Paladin (5th; fiendish boon: fiendish servant; APG) • Summoner (1st; eidolon; APG) • Summoner: Broodmaster (1st; eidolon brood; UC) • Summoner: Master Summoner (1st; lesser eidolon; UC) • Summoner: Synthesist (1st; fused eidolon; UC)
Feats that improve effective levels (bonuses capped by HD): Beast Rider (half-orc; +2 to effective druid level; ARG) Boon Companion (+4 to effective druid/wizard level; Animal Archive) Huntmaster (human; +1 to effective druid level; ARG)
