Create legends in scatter plt

Question

I create a mask of my dataset for plotting only No Animals materials, and when I draw this mask I have problems with the legends, because only the first material defines me and I don't know how to add the other 2 materials.

import numpy as np
import umap
import umap.plot
import pandas as pd
import matplotlib.pyplot as plt
from IPython.display import display,HTML
import cufflinks as cf
cf.set_config_file(sharing='public',theme='ggplot',offline=True)
import seaborn as sns

palpations = np.load('big_matrix_16384.npz',allow_pickle=True)
X = palpations['arr_0']
embedding = umap.UMAP(n_neighbors=50,
                     min_dist=0.2,
                     metric='correlation').fit(X)
emb = embedding.transform(X)
mask_1 = Data["Tipo"]=="Animal"
emb_tipo_1 = emb[mask_1]
cmap = plt.cm.Spectral
c =[sns.color_palette("Set2")[x] for x in data_tipo_1.Material.map({"bone":0, "cartilage":1, "liver_raw_piece1":2})]
plt.scatter(emb_tipo_1[:,0],
         emb_tipo_1[:,1],
         c=c,
         label=np.unique(data_tipo_1.Material),s=10)

plt.gca().set_aspect("equal","datalim")
plt.title("UMAP muestras Animales.")
plt.legend()

enter image description here