Claim: Comollo means Little Jacob, and has five variants, one of which is Jacobellis.
Evidence: According to the Dizionario ragionato dei cognomi (Annotated Dictionary of Surnames) by Frangipane, Comollo is the truncated and endearing form from the proper name Giacomo (Jacob): Gia→como→comollo. It is less probable that it is a toponimic from Como, because there are many similar surnames that maintain the original stem, such as: Giacomino, Giacomelli, Giacomolli, Giacometti, Jacobellis, Jacobacci and so on. 
Comollo Little Jacob (truncated) Comolli, Comelli, Comino, Giacomelli, Giacometti, Giacomino, Jacobelli, Jacobellis and similar