Green snake of death

I recently purchased an Apple Watch from someone & when I received it it was charged worked great & then it died I went to plug it in & it won’t turn on. So when it’s not on the charger it’s showing the red snake & when I put it on the charger it shows the green snake. I’ve also tried holding both buttons down to reset it & nothing is working for me! Also leaving it sit on the charger it does become a little hot. Any suggestions on what might help fix my Watch??!!!