Well, they're not exactly mottos, but they're cute!
 
Smokey: "I gave you kisses, so put me down!"
Merlin: "Must (pant, pant) eat (pand, pant) your (pant, pant) toes!"
Loki:   "Life is like a chew toy..."
Pirate: "God made sleepy sacks just for me."
Lance:  "If at first you can't beat them up, try harder."
Nikita: "If they look at you, sniff you, or try to give you kisses,
         scream!"
[Posted in FML issue 3944]