SILVIO
Silv
Silvs
Silvey
Silvinator
Silb
Silbs
Silbee
Silbadee
Silbadilbadee
Sliv
Slivio
Slibidee
Slibadibadee
Slibs
Silbinator
Silbydee
SillyCat
Sillio
Sweets
Sylvester
Fussy Cat
Fussbudget
Fatso
Fat Boy
Fat Cat
Fat Butted Cat
Booger
Boogerrooger
Booger Bear
Boog
Big Boy
Big Fat Cat
Mr Cat
Mr Sil
Mr Silv
Mr Silvio
Mr Slibs
Mr Big Fat Cat
Mr Booger
Mr Sweets
Mr Mister
or just plain "hey cat"
