Yes indeed. It's a magma cube. Strange enough I was searching for it. Weirdly I was totally oblivious I had collect 3 later on that day. It takes time and determination. You don't
have to collect them all. Shiny one's are worth collecting than regular as they give you more of a boost to level up. in which case you have more entries to win a competition. Good luck & I hope you will find your long lost egg.