In chapter 2 the glimpse of the newspaper ad states that his "little brother" is a snake.
I agree with the folks saying that the ML is the missing "little brother", but this does bring up some questions:
If you're a snake and you left behind a dried snake penis...
1. WHOSE dried snake penis is it?
2. Will it not cause awkwardness down the line in future if your partner sees your penis as an ingredient?
Lol.