Carlos was left as an orphan on the doorstep of the Huispas family, a Mobgoblin household in the East End.
He was raised there alongside his closest childhood companion, Alejandra, a fellow ratfolk who later left to pursue a career on the stage.
Tom describes their parting as two tails curving into a heart that slowly breaks apart.
Carlos joined the Mudlark church fighting for the rights of the verminous peoples.
As a member of the Mudlark church, the Flow flows within him.
He begins his career as a spy, but despite all his hard work, never rose above the rank Tide Priest.
A big raid on a Mobgoblin warehouse was planned, but his ledger went missing and the raid was called off.
He was demoted and nearly expelled.
Silt Saint Vulpin gave him one last chance: embed himself near the Black Tea, identify the Tea King of Donlon by name and face, and if possible deliver the tea to the church.
He is on that mission now. The crew does not know.

His last name sounds like 'whispers'. 

The night at Esme's: 
The Mudlark Church has heard Carlos' prayers and have a mission for him:
Observe Esme's and take down all the names of the Mobgoblins entering. 
Alejandra asked him for the list of the names. Unbeknownst to him, she gives the list to Maureen. 

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