Sans is Flabbergasted

Listen up, buttercup. Sans is acting all surprised, right? Then Gaster replies with some Wingdings and hand symbols. It's funny because it's a secret language thing from the game Undertale. Gaster speaks in symbols 'cause he's a mysterious, out-of-this-world character. So, basically, you're laughing at the weirdness of video game characters talking in code. It's also kinda funny 'cause you're too slow to understand it without me holding your hand, aren't ya?