Board Thread:General Discussion/@comment-26006155-20181123023529/@comment-26006155-20181203190751

(peers in before sleep claims him again)

Sans actually isn't lazy. In the ending where Papyrus becomes ruler of the Underground, Sans works tirelessly behind the scenes to keep everything running.

The reason Sans is Grillby's #1 customer is because he's a time-traveling adventurer (just like Frisk..) who eats tons of monster food to replenish health.

Sans' laziness is just like his pretending to be a skeleton.. an act.

Undyne might write off Sans as a lazy fool when he allows Frisk to run right past his guard station while she was chasing him.. but Undyne would never have tolerated open treason.