”That's sad. Regards, Sadfrogs.”
Sadfrogs is the cousin of the American meme Pepe the Frog. He is known for being depressed.
It all started when in the early days of /int/ a Finn drew a crappy frog and asked if this could replace the American meme he is bored of seeing. Amazingly, this worked. Sadfrogs has since evolved into a mini-meme, with variations such as "That's mad, regards madfrogs" and "That's deal with it regards dealfrogs"