I Have Wondering Can You Do Some Crossovers

Example

Monster Legends X Undertale
Can You Get A Team Up With Toby Fox To Put His Monsters In Your Game
Undertale Is Full Monsters Like

Sans The Skeleton
The Great Papyrus
King Asgore

These Are A Few Examples, They Would Look Great Monster Legends
So Is It Possible To Do A Crossover Like This Or If It's Not I Understand

Hi and welcome to forum

i think the idea is interesting but it due to copy rights not sure if is possible