-qui.

Headword: 
-qui.
Principal English Translation: 

older form of "-ni", one who does that thing (tlatoqui = tlatohuani)

Attestations from sources in English: 

1. plurals are formed from this form: e.g. tlatoque or tlatoqueh
2. combining forms, -ca-, also come from this form: tlatocatlalli

An example of one who does the specified thing would be "petlachiuhqui," one who makes petates.