Taken from an anon in another thread regarding new types:

"Monster type. Just as a sizable chunk of Normal types were retconned to Fairy due to their "cute" designs not allocated to a specific animal/living thing (barring Granbull), a Monster type would handle a portion of Pokemon who are "grotesque" in design and yet not allocated to a specific animal/living thing.

>Attacks are strong against:
Fairy, Fighting, Bug, Normal, Steel
>Attacks are weak against:
Rock, Ghost (x0), Ice
>Monster types are resistant to:
Fairy, Fighting, Ghost (x0), Fire, Water, Grass
>Monster types are weak to:
Poison, Ice, Dragon, Rock
>Retconned:
Lickitung (Normal/Monster), Snorlax (Normal/Monster), Kangaskhan (Monster), Exploud (Monster), Druddigon (Dragon/Monster), Marowak (Ground/Monster), Garbodor (Poison/Monster)"

How would this impact the game? Does how it interacts with other types make sense, and would it offer new utility to types that are currently underused? Another other mons you would like to see retconned? Do you agree with this new type conceptually? Feel free to post ideas for new types here as well.