I found my eel on the floor when i got home

[DrPepper]

So i got home from work, I went to go check my fish tank because i have recently bought a Black Spotted eel and wanted to check how it was doing. I know its not a salt water fish but I thought I would post something anyway, maybe somebody can help. I didn't see him in the tank and i found my pecostomas had uprooted his hiding spot and I couldn't find him anywhere. The only opening was a small hole in the back witch was covered with a small plank that looked undisturbed. I reached in to sift the sand a little bit to see if he was maybe hiding under but i couldn't find him. I stepped on a tac on the ground and I saw my eel about 4 feet away from the tank on the ground. I picked him up and used a container to suspend him with water flow still going in and out and thats where he is now. He doesn't seem to be out for long. He was covered in mucus and still seemed plump like he was when i left. So i think he has only been out of the tank for maybe a couple hours. He seems stiff but hes still plump and isnt hard. If anybody could help with this it would be greatly appreciated. So far a lot of mucus has come off.