An Elf and an Orc Had a Little Baby 2 - Page 88 contains the rules for mixing and matching upbringings and the point system for it, while page 2 explains that you get 16 racial points.

Prerequisite: Warlock

You learn the Find Familiar Spell. This homebrew background would be an addition to the upbringing and racial points rules from Elf and an Orc had a Little Baby 2. In exchange for a total of 6 points (which can come from your upbringing, racial bonuses, or both) you gain the ability to occasionally summon magical tattoos as described in Tasha's Cauldron of Everything. This works that whenever you cast the Find Familiar Spell, you may roll a d100. If the number rolled on the d100 is equal to or lower than your warlock level, your familiar appears carrying a magical tattoo needle that was gifted to you by your patron. The tattoo on the needle is up to the dungeon master's discretion.