Here is the "Travel Mug" from the Sega Shop online store in 2018.
It has a shiny metal screw-top sipper lid (so it won't spill easily) & a classic theme. It has 16 bit style pixelated art all the way round. It alternates various sprites of Sonic, like running, jumping & rolling. He's depicted over a line of rings, the usual Green Hill Zone ground & under that different sizes of the Chop-Chop fish badnik. (Why sizes though? ChopChops are all always the same, they probably did it for variety) There's also the classic logo at the top.
The art is under a clear plastic casing, which is good because that means it won't wear off during washing or normal use. This also helps the cup keep easier to clean, as does the wide top so you can reach into it to scrub.
This is 13 dollars at the Sega Shop in summer 2018.