In other galleries you will find photos of Lucy (alias El Gato), a food obsessed feline tabby. While she was technically not around at the time that Henri Rousseau painted this in 1891, I'm sure he was channelling her spirit at the time.
Officially called "Tiger in a Tropical Storm", this painting is also known under the name "Surprised!" and is one of a number of jungle-based paintings that Rousseau executed during his lifetime. It is, however, probably the least stylised of those works. While it would be an exaggeration to say that it's photorealistic, it's far less rigid than many of the works that he did on this theme. The structures and colours flow a lot more than with some of his other works, where there is a fairly rigid demarcation between them.
We don't see who is being "surprised" in this painting; we see the hunter, but the hunted is out of frame on the right-hand side of the image.
Rousseau did not study as an artist, instead becoming a government employee and tax collector. However he clearly always had an interest in art since he had won prizes for drawing at school and exhibited at the Salon des Indépendants from 1886 when he was 42 years of age. He was regarded as being a "naïve" (in the stylistic sense) or "primitive" painter, although he clearly knew his way around a paintbrush and a palette. The amount of layering in this scene, for example, requires a high degree of skill.