1: Place the frog legs in a nonreactive baking dish or a resealable plastic bag. Season with coarse salt, black pepper, smoked paprika, and the minced garlic. Drizzle with extra virgin olive oil and lime juice. Cover and refrigerate for 1 hour.
2: Make the scallion butter: Melt the butter in a small saucepan. Add the sliced scallions and cook until the scallions are sizzling but not browned. Set aside and keep warm.
3: Make the salsa: Combine the salsa ingredients in a mixing bowl and stir gently to combine. Add lime juice to taste. Set aside.
4: Set up your grill for direct grilling and heat to medium-high. Brush or scrape the grill grate clean and oil it well. Arrange the avocado halves (cut sides down) and frog legs on the grill grate. Grill the avocados until the cut sides are lightly browned, 2 to 3 minutes. Grill the frog legs for 3 to 4 minutes. Turn, then baste with the scallion butter. Grill until the legs are cooked through, 3 to 4 minutes more. Baste once more with scallion butter.
5: Grill the tortillas: Lightly brush the tortillas on both sides with the scallion butter. Arrange on the grill grate and grill for 1 to 2 minutes per side, or until lightly browned and crisp.
6: Build the tostadas: Peel and dice the avocado. Spread a small bit of gochujang on each tortilla. Add some avocado and a spoonful of the salsa. Top with 2 frog legs and sliced scallions. Serve with lime wedges for squeezing.