Catastrophically Kept

Camilla Caterpillar kept a caterpillar killer cat
A caterpillar killer cat catastrophically she kept.
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Amelie Robertson the human is no Camilla the caterpillar. She actually leads a very normal life (annoying family, crazy friend, unrequited love (or 'friendship' as he likes to call it) with one of the town's hottest hunks). And she's pretty sure she won't change into a butterfly soon. Or ever.
But what Amelie the human has in common with Camilla the caterpillar is something that she ends up catastrophically keeping... the human-killer non-human. If that makes sense.
*
(No, this is not a vampire story. Nor is there anything about wolves. Sorry.)
Cover photo credit > http://theycallmequietgirl.deviantart.com/art/Sunflower-318711005
Cover done by moi.
Tongue twister, to which I owe for the title, by > Mike Jubb (from my poem book 'The Works' by Paul Cookson)