Garden wildlife cartoon and garden gnome cartoon
Cartoon of a garden pond that has garden gnomes round the edge holding coils of barbed wire in order to keep cats away from the pond
The garden gnomes are being used to protect the frogs and fish in the pond from the local cats.
Cats are a problem around garden ponds, especially in the frog spawning season.
Garden gnomes are normally holding fishing rods, spades, wheelbarrows or other gardening implements. Gnomes holding barbed wire is a novelty.
Part of the joke is that this particular type of garden gnome is actually useful rather than just being decorative.