So I'm starting up a Ravnica campaign and one of my first time players wants to play a "Tinkerer" fighter.  First thought was to suggest the Izzet Guild, make sure to research the crafting rules, and that should work. 

Then I started helping him with his stats and asked if he wanted to use ranged or melee weapons for combat.  He looked at me puzzled and said, "I thought I was going to be a tinkerer?"  Now I feel like I completely missed what he wanted to do and am open to suggestions   ^^;

I considered looking into Artificer for him, but he's set up to be the group's tank and the other players are a Druid, Cleric, and Wizard.  I also noticed that the Lizardfolk race has a natural crafting feature, so I considered combining it with Izzet we can rule the natural weapons he would make could be one off "gadgets" he cobbles together with trash and call him a Vishano instead, but feel like I would have to ask the rest of the group if they were okay with taking that liberty.  Thoughts? 

Really any race/class combination can be a tinkerer with a tinker tools proficiency.

Lizardfolk reskinned as vishano is suggested by GGtR so no issues there.

Personally, I would be against the natural weapons being reskinned as gadgets and would recommend regular weapons get that treatment instead.