What exactly is an Beanie?

The Beanie can be described as a tiny, stuffed animal, usually made of wool, felt, or cloth, which is often given away at sporting events. Many collectors claim that they don't feel any feelings of connection to the items in their Beanie collection. Instead, they invest many hours studying the market and learning about its complexities. Additionally, they realize that their hobby may be a little silly and that some people might consider them insane.
Beanie Babies were distributed during a baseball game.

Since 1997 in 1997, over 22 Major League Baseball teams have distributed Beanie Babies during baseball games and attracted thousands of fans to the stadiums. Ty has worked with MLB to create special tags for Beanie Babies to commemorate players as well as special events. These include Mac the Cardinal, Rocket the Blue Jay, and Sammy Bear. Bear. Each one has its own unique giveaway day.
They are important

Vintage Beanie Babies are valued, depending on the condition and the rarity. Some collectors can be willing to pay up to $50,000 for an original 1992 Ty Beanie. Other collectors will pay more than $25,000 for a vintage 1995 Lefty the Donkey.
https://jasonfinger21.doodlekit.com/blog/entry/25076610/what-is-an-beanie  are constructed of cloth, felt, wool leather, silk, or

Felt is among the strongest fabrics. It is composed of tiny fibers which are interlocked in each direction. This makes it lighter than the woven fabric which is composed of twisted fibers in straight lines. It is also the strongest fabric as it requires the least amount of fibers to be strong. It is also waterproof and stain-resistant, and it is hypoallergenic.
They sport a clown face.

This  beanie  is adorned with a big clown face with a propeller. It is made of acrylic yarn and comes in one size that fits all. This clown beanie also has embroidery on the front as well as plush fur.

They are constructed of a brimless cap

The smallest hat, known as a beanie is constructed of wool, felt, fur, or hair. The materials are compressed and then shaped by a process of rolling, pressing, and heating.  beanie hat  is a brimless , flat top cap made from red felt. It is often used as a hat during winter, when the temperature is below the freezing point.