Every Mob that doesn't have a Display option gives an error with egg get command

Summary

title says it all really. Using MM dev 5.6.2 build 5013

Steps to reproduce

make a mob that doesn't have a display option, then use /mm m egg get command

https://pastebin.com/3pSNS7d3

Current behavior

https://pastebin.com/aBqqi9tP <-- error in question

Intended correct behavior

for egg to be given to me, but instead error is thrown

Server log file

https://pastebin.com/3L2rAe8M

Debug log snippet

Proposed fixes