My brother, aged (yes) about 4.
My dad took me fishing, and we caught mackerel. DB came over to watch is fillet and clean it, and my dad held a head up, and made it's mouth move "Hello DB! How areyou"
DB now thrilled to boots with new friend, and certainly won't allow his new friend to be used as fishbait or thrown away. Dad says yes, he can keep the head until bedtime.
unfortunately he then forgot, and mum doesn't know about it, and bearing in mind we are in a tiny caravan full of fishing equipment, it's a while before anyone notices the smell. but DB still won't let anyone throw his friend, which his has barbecue wrapped in tinfoil and snuggled under his pillow, away.
So a comromise is reached. Fishhead can live in a plastic bucket under tha caravan, as long as he doesn't come inside.
To prevent my brother taking it home, my dad had to cob it over a hedge while he wasn't looking.