There is nothing that generates arguments between gamers like the accusation of “cheesing up” a character, animal companion or familiar.
But nobody has the same definition of what that means. I’m not even sure of the derivation of “cheese” to mean exploiting some corner rule case or unexpected synergy to create a totally overpowered result.
So I’m going to list several items and ask “cheese or not cheese?” for each one. Here we go:
1. Giving your familiar wands which are triggered by the command word “ook!”
2. Taking a dinosaur raptor animal companion when your druid never encountered a dinosaur.
3. Using double-barreled pistols in each hand for a gunslinger.
4. Buying a dozen CLW wands.
5. Crafting wondrous items several levels above your caster level (using the +5 to DC rule for missing requirements for crafting).
6. Using your animal companion for a mount.
7. In point buy character building, dropping an undesired attribute below 8 to boost a desired attribute.
8. Crafting a “ring of true strike”.
9. Building a two-weapon fighting shield basher with shields on each arm.
10. Taking the “leadership” feat to create your own personal healbot.
11. Taking an ape as an animal companion, boosting its int to 3, giving it humanoid magic armor and magic weapons.