The cat to the right is not made from Lego, but is an example of the Pantonaef Modular Toys from the 1970s.
Verner Panton created the Pantonaef series for the Swiss company Nael in 1975. Comprising of just three types of pieces, they can be clamped together in various ways to create a limitless range of shapes. Instructions were available for creating abstract forms and animal shapes.
Not to doubt their entertainment value, but you wouldn’t want to give a child the Pantaef Modular Toys to play with as they are rather rare these days. 20th Century Marks currently has four sets available to buy that have already been put together in the shapes of a rabbit, cat, camel or cow. They do not give a price (which is always a warning sign) but they are likely to be expensive for what is now a very much a collectors item.
Visit 20th Century Marks for further information.