Kuiil is an Ugnaught moisture farmer and mechanic on Arvala-7 who helps Din Djarin track his quarry in the first season of The Mandalorian (2019). Nick Nolte voices him; the character is a puppet and animatronic build rather than an entirely digital creation.
An indentured servant who bought himself out
His backstory is delivered in a single line and reframes him completely: he worked as an indentured servant for three of his people's lifetimes before purchasing his own freedom, and he came to Arvala-7 specifically because it was empty. When Din offers him a share of the bounty he refuses it, explaining that he has spent a lifetime becoming free of servitude and does not intend to enter into obligation again. He helps anyway.
The droid
His most consequential act is rebuilding IG-11, the assassin droid Din destroys in the first episode, from salvage. He does it patiently, teaching a blank neural harness from scratch, and he makes an argument the series keeps returning to: droids are not good or bad, they are only what they are programmed to be, and this one is now programmed to protect. That reprogrammed droid saves the Child's life after Kuiil is killed by scout troopers.
"I have spoken"
The catchphrase does a lot of work. It is not a joke, or not only one — it is a full stop, the verbal habit of someone who spent generations being talked over and has decided he will not be again.