Melodraspastic is a melodramatic spastic ie, someone who is extremely mentally 'challenged' yet posesses the further unfortunate quality of also being overtly 'gobby' and extroverted.
Miss Rees: I will assign you all adjectives for your to write a paragraph on, Lucy, yours is 'melodramatic'
Lucy: ME?!?!?....Melodramatic?! *spitting everywhere*
Here, Lucy demonstrates her ability of melodraspastication, not realizing her spontaneous outburst of excitement and delivering in a predictably retarded way.