Witch's Nest is using the tap symbol to limit you to using the ability once per turn, much as we use it on artifacts
The back side is also interesting
Collector Boosters Collector Booster Contents 5 Traditional foil commons 4 Traditional foil uncommons 1 Traditional foil seasonal basic land Spring 40% Summer 30% Autumn 20% Winter 10% 1 Traditional foil rare or mythic rare card 60 Traditional foil rares (85.7%) 20 Traditional foil mythic rares (14.4%) 1 Non-foil or traditional foil Commander extended-art rare or mythic rare 4 Non-foil borderless Commander face mythic rares (5.63%) 1 Non-foil borderless Commander Imagine: Courageous Critters rare (2.82%) 3 Non-foil borderless Commander Imagine: Courageous Critters mythic rares (4.23%) 4 Non-foil borderless Commander mythic rares (5.63%) 28 Non-foil extended-art Commander rares (78.9%) 4 Traditional foil borderless Commander mythic rares (2.8%) 2 Non-foil alternate-border rares or mythic rares 5 Borderless mythic rares (6.58%) 1 Borderless field notes rare (2.63%) 6 Borderless field notes mythic rares (7.89%) 1 Borderless field notes mythic rare (0.6%) 35 Showcase woodland rares (92.1%) 7 Showcase woodland mythic rares (9.21%) 1 Borderless planeswalker mythic rare (1.32%) 13 Extended-art rares (34.2%) 12 Borderless Imagine: Courageous Critters rares (31.5%) 8 Borderless Imagine: Courageous Critters mythic rares (10.53%) 4 Borderless Three Tree City rares (2.63%) 1 Borderless Mitsuhiro Arita Lumra, Bellow of the Woods mythic rare (0.6%) 1 Traditional foil alternate-border or raised foil rare or mythic rare 5 Traditional foil borderless mythic rares (3.07%) 1 Traditional foil borderless field notes rare (1.23%) 6 Traditional foil borderless field notes mythic rares (3.68%) 1 Traditional foil borderless field notes mythic rare (0.31%) 35 Traditional foil showcase woodland rares (42.95%) 7 Traditional foil showcase woodland mythic rares (4.30%) 1 Traditional foil borderless planeswalker mythic rare (0.61%) 13 Traditional foil extended-art rares (15.95%) 12 Traditional foil borderless Imagine: Courageous Critters rares (14.73%) 8 Traditional foil borderless Imagine: Courageous Critters mythic rares (4.91%) 4 Traditional foil borderless Three Tree City rare (1.23%) 1 Traditional foil borderless Mitsuhiro Arita mythic rare (0.31%) 10 Traditional foil borderless Special Guests mythic rares (3.07%) 21 Raised foil anime cards appear in 3.66% of boosters
Brawl, Commander, Legacy, modern, Pauper, Pioneer, Standard, Vintage Constructed formats let you build your deck well in advance
Spike Cannibal When Spike Cannibal hits the table, every +1/+1 counter from every creature moves onto it
