a while ago I saw a very cool artwork by Javier Burgos and really liked it ( check his great artwork https://www.artstation.com/artist/javas )
I was thinking about practicing to sculpt with symmetry off and from a sphere(Groot) , zsphere (Rocket) (I don`t do this as much in my daily work) then take it all the way to be a realtime model

sculpted and modeling zbrush and max , rendered in marmoset toolbag , used substance designer for texturing