Morveu is a slang term that is both used in Québec
. It comes from "morve" which is snot
. While morve means so, morveu does not. Morveu is connotatively
equivalent to "little puke." And seeing as puke and snot are bodily fluids, it fits perfectly.
By the way, this is one of those vulgar expressions where you can use on TV (i.e., Simpsons in French -- Homer tends to use this term to address to Bart).
Reviens icitte mon petit morveu!
Come back here you little puke!
Revenez icitte mes petits morveux!
Come back here you little pukes!
Note the 'x' is added for the plural