Separate names with a comma.
Bumping thread in 2018 because this would be VERY useful.
Just tested with MythicMobs versions 4.3.0 and 4.3.1, neither of them work.
Thanks for the help! The biomes weren't the problem, they were working just fine and I tested them on other mobs. I just forgot to add mobType.
I have two random spawners that spawn an Angry Squid. They are set to replace, so they should spawn only where vanilla mobs spawn....