turn into a frog

[coolfool_sin]

I've read Jeffrey Archer's A Matter of Honour. It's, once more, a cute novel. There're three sentences I can't understand or ain't so sure. They're as follows:
1. "... You do not catch a poacher by offering him rabbit stew."
2. "Don't do that, Adam, you might turn into a frog. ..."
I've consulted a dictionary. One of explanations says frog: noun (oft. cap.) Slang (disparaging & offensive) a French person or a person of French descent. Does it fit here?
3. ... managed to keep a straight face.
Does straight, here, mean serious?
You're highly appreciated if you'd give a helping hand.

[andy-hughes]

The first sentence infers that by offering a poacher (someone who traps animals for food illegally, usually on private land) a rabbit stew, you are in fact encouraging him - poachers often catch rabbits which they sell for food.

The sceond sentence is more likely a joking warning that the child may become a victim of a witch's spell, and actually be turned into a frog - the amphibious animal. The warning would not be meant to be taken literally - just a jokey way of stopping the child doing something he shouldn't.

Yes, it does mean serious - probably while the temptation was to laugh, or at least smile, but keeping a 'straight face' means giving nothing of the person's reaction away in their facial expression.

[Clanad]

I can certainly see the reasoning behind andy's answer to the first question, but I would offer a slightly different interpretation. To actually "catch" a poacher takes serious work of detecting, following and gathering evidence to convict the poacher. Offering an easily made bowl of rabbit stew is not a substitute simply because it contains one of the poachable animals. Therefore, the speaker of the homily is implying to go do the hard work and don't skim by with a poor substitute... in my opinion...

[Steamcarrot]

My interpretation of the first one is that using rabbit stew as a bait to catch a poacher won't work as he'll have plenty of the stuff anyway. Possibly need to find out more about what context it is used in.