A meme token, the first ever token deployed on Uniswap V1 that was originally deployed by the founder of uniswap in 2018, there was $50 in liquidity left on V1 so the community bought up the V1 Tokens and added Eth to the V3 uniswap pool to make the token tradeable, being the oldest token ever on Uniswap.
The meme itself is based around Hayden who is the founder and ceo of Uniswap, he created the coin probably for tesing purposes back in 2018. 99.9% of the supply is owned by the uniswap founder/uniswap labs wallet. 0.1 $HAY out of 1,000,000 Hay was supplied into the liquidity pool on V3 from getting those tokens from V1.