cardfight vanguard booster box 3 Vanguard: Cavalry of Black Steel [EB03] or collecting featured units from the release Cardfight!! Vanguard Booster Pack 03:

EDIT: As mentioned below, The Red-Gloved Man, Summoned Hound and similar can help with the Homunculus statline - but I'd still advocate for not becoming the Homunculus in the first place

Although it is heavy as it is, it is quite plain with only an overall weakening effect that consumes his GY resources and a penetration effect without multiple attacks

Considering the ease with which life is gained, and in big chunks, though, this has potential

(2023-02-04) If more than one creature with toxic deals combat damage to a player at the same time, those counters are placed as a single event, and the ability triggers one time

Note that +1/+1 counters/Food tokens don't have a mana cost, so their mana value is 0