>>32572059I think
>>32572045 is getting muddled up with Mr. Mime, who is available on the section of Route 2 accessible through Diglett's Cave.
Lickitung is on Route 18, at the bottom of the Cycling Road. Even then, you need a Slowbro to trade for it; Slowbro is rather hard to get in RB, requiring you to use the Super Rod on Route 23 of all places or wander round the Seafoam Islands and hope you get the lucky 1% encounter (or grind a Slowpoke up to Lv37). It's no wonder no-one really used Lickitung in Gen I.