Elvis smiled slightly, to be honest, he could completely understand Snake.
The reason why he was so anxious in finding the three little wolf cubs was not because he had any special favorable impression towards them. Instead, it was because Gu Mengmeng would never give up no matter what if she could not find them.
And although Snake silently consented Elvis and Lea in searching for the kids in the Snake King Valley, he might be helping Ellie to hide the kids on the other hand.
There was no reason other than....Gu Mengmeng changing her next agenda 'to leaving him' once she found her kids.
The promise and baseline he gave her was that the kids being controlled by Ellie were safe and sound but Gu Mengmeng could never find them.
That way, she had to stay behind to continue searching.
What if Gu Mengmeng suddenly lost interest in her kids one day and thought it through to just give birth to another nest of babies?