I'm Sad: 03/03/20
I'm Sad by Michael Ian Black and Debbie Ridpath Ohi is the sequel to I'm Bored (2012). This one focuses on the emotional wellbeing of the flamingo who is feeling sad.
More broadly, the flamingo is probably depressed. He expresses concern over always feeling sad. He worries that his friends won't like him if he continues to be sad tomorrow.
The girl and the potato do their best to cheer up the flamingo. The girl's approach is similar to her anti-boredom one, namely, playing pretend. The potato's approach, meanwhile, is more down to earth (pun intended).
Ultimately, though, what helps is a shared inside joke and the reassurance that they will still like the flamingo if he continues to feel sad. He decides knowing he'll still have friends is enough to feel a little better, even while he's still somewhat sad.