For Mother's Day:

This is a tricky one. We've seen lots of fics over the years, where a certain mature female-character takes the role as Spike's "mother-figure." We've had:

1. Celestia and Spike (a personal favorite of mine)
2. Twilight and Spike (Twilight's both his mother and sister)
3. Twilight's mom and Spike
4. There was even a fanfic series of Princess Luna babysitting Spike while Twilight was away

Synopsis:

With Mother's Day coming soon, Spike goes on an epic quest to search for the Gift Givers of the Grove – Aurora, Bori, and Alice – to get the "ultimate" mother's day gift for his mother-figure.

Recap: The Gift Givers are the magical reindeers Pinkie Pie meet in the holiday special The Best Gift Ever, courtesy of Prince Ruthorford. They displayed their powers of giving gifts, according to past, present, and future. They speak in prophecy. Granted, they may have been featured in a Christmas special. But who says their powers only works on Christmas?

For Father's Day:

Depicts Spike and Scorpan.

The image you see was drawn by a TheBrokenCog. And in their description, they wrote:

Growing up, Spike never really knew his parents, who they were or what they were like. And because he was raised (and constantly surrounded) by many, many beautiful women, he never really had a dad, a father… or even a father-figure.

Until the day he met Scorpan.

At first, Scorpan didn’t know how to interact with Spike. But with Celestia’s help, Scorpan slowly grew into the role of Spike’s mentor, guardian and male role model, more like a caring uncle than anything else.

Spike would tag along with Scorpan almost wherever he went, and over time Scorpan became very protective of the boy. Scorpan wished the day would never come when Spike would grow up, just so he could continue to guide the young boy to adolescence and eventually adulthood, so that he could become a good man… if for just a little while longer.

But Celestia knew that Scorpan had done a good job.

“Happy Father’s Day, Dad! I love you.”
“I love you too, Son.”

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Unfortunately, while you have great ideas, I'm afraid I don't have the time and energy to tackle them. Still, these ideas ARE great and I wish you luck in finding somebody who DOES have the time, energy and love to do this stuff right.

7959026
Not bad. Even if it many also assumed the Sparkle’s would be parental figures to Spike we never got a real chance to see what they thought of him. And the Zeppelin episode could’ve been a good chance since they were all together but they single Spike out just so they can make him appear generous to do Twilight’s work