Mark Rosewater's name is on one of Magic: The Gathering's creatures. Well, sort of.
Early on in Magic, Wizards of the Coast instilled a "no vanity" rule as a number of the game's early cards were winks, nods, or even anagrams of Magic employees, friends, nicknames, and pets. Seeing it get out of hand a bit and not wanting to cause any ill-will, it was all ended a few years in.
While reprints are still allowed and additional cards based on those creatures are as well, in general, it doesn't happen outside the Un-sets and the rare celebration card.
"The concern is that vanity cards influence how people behind the scenes make choices about cards," said Mark Rosewater in 2016.
However, Rosewater himself managed to snag one in...kind of a unique way.
So, first a little context for you: Mark Rosewater's nickname in "Ma Ro," coming from the first two letters of his first and last name. In 1996, while going over cards for Mirage, the developers realized that they still had an open spot for a rare card. Bill Rose, one of the lead designers, put in "Ma Ro" there as a placeholder, as his nickname was also his handle for internal communications. Basically, he put this down to figure out, not intending it as a name.
But then the creative team did a pass. Not known of his nickname or the placeholder, they saw the name as "Maro" and rolled with it, as they kind liked the name for a creature. By the time everyone else saw it and that it was about ready to go, well, they rolled with it too. And Maro became this:
Not only was Maro a reference, but it became something of a long-time running name as, still today, cards that care about your hand size are sometimes referred to as "maro" cards.
Even more, maros have had a long legacy since then. Every few years a new maro creature comes around.
Saviors of Kamigawa alone had five of them come out. While this is now a common creature thanks to so many following in their footsteps, maros all began with a placeholder name that they just kept around because they liked the sound of.