Sorry for the delay. :)
King bettas are, I heard, not full fledged giants but half giants.
Well my king is a little aggressive, and a little piggy X3, and while he did settle in with the idea of a snail tank mate when I first put him in with the snail he went and took a bite o'snail. But left him alone after that.
I'm pretty sure he would eat the shrimp, and he might even attack a frog (that is IF I could find one). Peaceful fish I don't know what he'll do but he is quick and a little ruff.
Mabey I'll get a blue mystery snail, or some other snail as they fun to watch and funny to watch magilla swim there just staring in confusion. X3
Also I love the name Bilbo Froggins! XD