“Monkey Puppet” features the image of a monkey puppet from a children's TV show. There are several images taken of the same puppet that are used as memes, but generally they all show the puppet either looking shocked, nervous or sad.
Typically the image is combined with a caption referring to a particular scenario, or otherwise used as a visual way of showing the poster's reaction.
The actual puppet was a character in a Japanese children's TV show called Ōkiku naru Ko or (in English) Growing Children, which ran from the years 1959 to 1988.
The meme was first popularized by the Spanish-speaking portion of the internet. It usually featured captions referring to everyday annoyances, with images of the monkey puppet looking sad and pleading and the words "No ahora, porfavor" ("Not now, please") placed below the image.
Clips of the original TV show were uploaded on Youtube with English subtitles, and were eventually converted into a reaction GIF.
Twitter user @ultkjongin uploaded the GIF in response to a news article, and the meme soon took hold of the English-speaking internet after this was covered by the Daily Mail.
The meaning of this meme varies a lot, partially because many different images of the monkey puppet are used in various circumstances.
Overall, the monkey puppet is primarily used as a reaction image. Depending on the photo used and the context, the image could be intended to display the poster's shock, sadness, confusion or discomfort and could be intended to be displayed either genuinely or sarcastically.
The meaning of the monkey puppet in the Spanish-speaking internet is more fixed, with the image usually being used to describe someone pleading with fate on account of a minor inconvenience, drawing humor from the hyperbolic contrast between the sadness and helplessness of the puppet and the (usually trivial) situation described in the captions.